MLADEN ANTONOV/AFP/AFP/Getty Images
Angkor Wat, Cambodia: Angkor Wat was a massive city with a vast network of roads, houses, canals, ponds and temples across the Cambodian countryside.
FILIPPO MONTEFORTE/AFP/AFP/Getty Images
Rome, Italy: The Colosseum -- a nearly 2,000-year-old stadium in the middle of a modern city -- is one of the sites that reminds visitors of Rome's glorious (and gruesome) old era.
Courtesy Dan Kitwood/Getty Images Europe/Getty Images
Istanbul, Turkey: Istanbul's historic core of Hagia Sophia sits a short stroll away from the Ottoman Empire's Topkapi Palace (pictured here), which houses artifacts including Moses's staff.
Martien Jansse
Bagan, Myanmar: Long hidden from international view by Myanmar's military government, the treasures of Bagan -- an 11th-century complex of more than 2,000 Buddhist temples -- is built along the Irrawaddy River.
JOHAN ORDONEZ/AFP/AFP/Getty Images
Tikal, Guatemala: Hidden in the jungles of Guatemala, Tikal was a Mayan citadel that reflects more than 1,000 years of cultural achievements starting from 600 BC. The structure in the picture is one of the most important temples in the site -- Tikal Temple I, or Temple of the Great Jaguar.
MOHAMED EL-SHAHED/AFP/AFP/Getty Images
Cairo, Egypt: In addition to the pyramids of Giza in the outskirt of the city, Cairo city boasts a history of over 1,000 years. The picture shows a view of Al-Mu'izz al-Din Illah Street, one of the most important historical streets in the Islamic quarter of Cairo.
Mohammad Reza Domiri Ganji
Persopolis, Iran: Persepolis regained its allure for visitors in recent years as Iran briefly enjoyed better relations with Western countries. The city was founded in 518 BC by Darius I, ruler of ancient Persia's Achaemenian Empire, and grew in grandeur until Alexander the Great sacked it two centuries later.
courtesy of Jeffrey Friedl, regex.info/blog
Kyoto, Japan: As imperial Japan's capital for more than 1,000 years, Kyoto has found a way to respectfully preserve its old traditions while eagerly embracing the new. There are more than 1,000 well-preserved Buddhist temples and Shinto shrines in the city.
Hemis/Alamy
Beijing, China: China's capital city has invested heavily in eye-popping modern architecture over the last two decades, but no new building speaks splendor like the city's historic heritage sites, including the Forbidden City.
AFP/Getty Images
Great Zimbabwe, Zimbabwe: As the kingdom of Great Zimbabwe grew into a trading empire from the 11th century, a royal complex expanded creating a terraced palace. Today, massive walls and narrow passages -- usually deserted -- still stand on the hilltop at Great Zimbabwe.
Craig Smith /CNN IREPORT
Timbuktu, Mali: Before the Sahara nearly swallowed the city, and before French colonialists swept through, Timbuktu was one of the world's most important centers of learning. Caretakers of the remaining manuscripts still use the same techniques to preserve them as the original librarians.
EITAN ABRAMOVICH/AFP/AFP/Getty Images
Machu Picchu, Peru: Sitting 8,000 feet high in the Andes, the mysterious Machu Picchu -- built more than 500 years ago -- attracts thousands of visitors a day.
ARIS MESSINIS/AFP/AFP/Getty Images
Athens, Greece: Athens' ancient monuments have found remarkable ways to coexist with modern Athens. Cafes and shops can be found in walkable neighborhood streets below the Acropolis (pictured here), making the ruins a part of Athenians' everyday lives.
Credit Jessica Lee
Petra, Jordan: With a history dating back to around 300 BC, Petra is known for its magnificent buildings carved into red sandstone cliffs. Gorges and canyons surround the ancient city, creating a maze of passages that helped keep it secret from Europeans for centuries.
AFP/AFP/AFP/Getty Images
Ellora, India: Ellora was carved out of the mountains, and this Indian monastic complex remains relatively unknown. The temples include Hindu, Buddhist and Jaina holy sites that were built over 400 years, beginning in the 6th century.
Shen Lu/CNN
Xian, China: China's ancient capital city is home to the famous Terracotta Warriors -- thousands of clay soldiers that fill the mausoleum of Emperor Qin Shi Huang. With excavation works still underway, it's one of the great archeological finds of all time.
DIBYANGSHU SARKAR/AFP/AFP/Getty Images
Madurai, India: In the heart of Madurai -- once an important capital city of Tamil -- sits Meenakshi Amman Temple, one of India's holiest sites. The current structure was built in the 1600s, with 14 gateway towers guarding the shrines covered in vibrant colors.
Susan Guice/UNESCO
Poverty Point, Louisiana: Largely unknown even to Americans, Poverty Point in Louisiana achieved the height of early human civilization in North America -- a complex trade hub reaching its greatest heights around 3,500 BC. It was built and used by hunters, fishermen and gatherers -- even though farming hadn't been established yet.
Ulet Ifansasti/Getty Images
Borobudur, Indonesia: The ninth-century Buddhist temple complex of Borobudur is the most visited site in Indonesia. The complex, completed in the early 800s, lay covered under volcanic ash and jungle for centuries until it was revealed in the early 1800s.
De Agostini Picture Library/Getty Images
Takht-i-Bahi, Pakistan: This Buddhist monastery was built in the first century, but fell out of use a mere 600 years later. Its hilltop location protected it against a succession of invasions, until the British came through and hauled off most of the surviving treasures. Meditation chambers here were once used by monks who brought Tantric traditions to this part of the world.
courtesy English Heritage
Stonehenge, England: It's believed that this prehistoric stone circle could have been built as much as 5,000 years ago and construction may have spanned over 1,500 years. The method by which the giant stones were transported here is still a mystery.
Joe Yogerst/CNN
Gondar, Ethiopia: The capital of the old Ethiopian Empire, Gondar suffered under repeated invasions from the mid-1800s. However several castles and churches -- including Fasil Ghebbi, a royal citadel pictured here -- remain, offering a look into one of the few medieval African cities that's still alive today.
Nimrud, Iraq: The capital of Nimrud, the world's first empire, was once a formidable city with massive palaces and temples to gods of war and writing. Ivory furniture, carved stone slabs, gold jewelry and crowns were all buried inside.
Nimrud, Iraq: However, much of this irreplaceable art and architecture was destroyed by ISIS in 2016.

Story highlights

Some ancient sites that have survived for centuries are troubled today

From Asia and Europe to the Americas and Africa, these sites provide history lessons

CNN  — 

Ancient sites that have survived centuries, or even millennia, haven’t fared so well in the 21st century.

The destruction at Palmyra in Syria, the Buddhas at Bamiyan in Afghanistan and Nimrud’s ruins outside Mosul in Iraq show how precarious the future can be.

Here are 23 best ancient cities you can visit – destinations that offer glimpses into humanity’s past and the ingenuity that people brought to creating wonders without computers or heavy machinery.

Some are recognizable. Others are easily accessible but lesser known. All make for intriguing travel.

Angkor Wat, Cambodia

Alex Ogle/AFP/Getty Images
So beautiful, so misunderstood. To get this sunrise shot, you're going to be fighting with a few hundred other tourists, all crowded around Angkor Wat's moat.
Pongpat Patumsuwon/CNN
Monks from the nearby temple can often be seen conducting Buddhist ceremonies inside Angkor Wat.
Pongpat Patumsuwon/CNN
Many tourists walk right by this statue close to the west entrance of Angkor Wat without realizing its significance, says Alison Carter, who works with the Greater Angkor Project. It's a large Neak Ta (local ancestor spirit) called Ta Reach. "I actually think this statue and its place in the community over hundreds of years is so interesting," she says. "The statue is likely of Vishnu (it's not clear), but inhabited by this powerful local spirit."
CNN
The faces of Angkor's Bayon Temple are believed to be representations of King Jayavarman VII, who ordered the construction of the temple in the 12th century.
"At the Bayon, everyone marches up to see the faces towers -- and they are great -- but I think the bas-reliefs encircling the lower levels of the temple are a real treat, especially those showing scenes from daily life," says Carter.
CNN
You didn't think you'd have the place to yourself, did you? Thanks to a little-known actress called Angelina Jolie and the film "Tomb Raider," this Angkor temple, famed for the large fig, banyan and kapok trees that are 'choking' the ruins, endures the bulk of visitors to the area.
Pongpat Patumsuwon/CNN
Some parts of Ta Prohm are blocked off to tourists. Archaeologists have had to strengthen certain sections of the ruins with supports out of fear they would collapse.
Chuck Thompson/CNN
In an effort to help tourists avoid sunset scenes like this, website Angkorsunsets.com, set up by the Cambodian authorities, offers suggested alternatives.
CNN
Made of red sandstone, Banteay Srei is one of the oldest surviving temples in the Angkor area. Famous for its intricate and well-preserved carvings, it dates to the 10th century. Archaeologist Roland Fletcher recommends visiting the Angkor sites in chronological order to get a better understanding of how the area developed.
Noel Hidalgo Tan
Noel Hidalgo Tan discovered these paintings of deities, animals and musical instruments on the walls of Cambodia's Angkor Wat in 2010. This photo shows the image after it was processed with software that helps to distinguish between similar color shades. Researchers said they've known about the paintings for some time, but the software allowed them to really get a good look at the detail in them.
Noel Hidalgo Tan
This was the original photo, before Tan used software to accentuate the colors. He said there are many walls with paint traces in Angkor Wat for those who want to give it a try themselves.
Pongpat Patumsuwon/CNN
Stegosaurus fossil? Proof that man walked the earth with dinosaurs? You can make your own call at Ta Prohm. The small carving, well-known to most guides, can be found in a doorway with other non-prehistoric creatures, including monkeys and birds.
Pongpat Patumsuwon
"The Devata [goddesses] at Angkor Wat do all seem to be quite distinct from one another, leading several people to speculate they might be portraits of real people," says Carter. Case in point, this one-of-a-kind smiling lady, found near an entrance gate at Angkor Wat. You won't find another Apsara or Devata carving among the thousands at Angkor that shows her teeth says Cambodian guide Tong Hann.

In the 12th century, the Khmer took their vast understanding of the known universe and sought to recreate it in miniature.

The result was Angkor Wat, a sprawling city designed to impress with meticulously arranged moats and towers, and walls covered in astonishingly detailed bas reliefs of Hindu deities.

The ancient Khmer took a broad view of scenes worth preserving.

While many are celestial or holy in theme, other murals detail mundane acts like preparing supper.

Angkor Wat stretches over 500 acres within the Angkor Archeological Park, a large area covering more than 150 square miles.

The main temple receives packs of tourists, but many lesser-known temples offer a chance to wander through old Khmer capitals, which were built from the 9th century onwards.

Rome, Italy

Visiting a city as beloved as Rome comes with particular hazards: the crowds, the cheesy souvenirs, the young men in full gladiator regalia waiting to pose for selfies with tourists.

And yet there are few places like it.

Take the Colosseum – a nearly 2,000-year-old stadium in the middle of a modern city.

In the days of actual gladiators, 50,000 spectators would gather with the emperor for bloody contests to the death.

The Colosseum had the original retractable roof, a whizz-bang contraption called a velarium that used sail technology to rig canopies to shelter crowds from sun and rain.

And we’ve not even mentioned the Vatican, the catacombs or the Forum.

Istanbul, Turkey

Istanbul loves to depict itself as the city straddling two continents.

What’s most remarkable is the way the city straddles great periods of history that pile up and fold over themselves more naturally than anywhere else in the world.

Construction by successive empires from Byzantium to Constantinople to modern Turkey have bequeathed Istanbul an instantly recognizable skyline that merges elements from all those eras.

In the historic core around the iconic Hagia Sophia, the Byzantine-era Hippodrome circus sits a short stroll away from the Ottoman Empire’s Topkapi Palace, which houses artifacts including Moses’s staff.

Surrounding it all is a thriving modern city with top-notch dining, galleries and architecture that make Istanbul one of the world’s most important cultural centers.

Bagan, Myanmar

Courtesy Nicolas Asfouri/AFP/Getty Images
Less crowded than Angkor Wat and Machu Picchu, but just as magical.

Long hidden from international view by Myanmar’s military government, the treasures of Bagan returned to the spotlight after political reforms began opening up the country.

Here, over 2,000 Buddhist temples fill a plain along the Irrawaddy River, creating an ethereal landscape.

The crowds remain far smaller and more adventurous than the tour groups that fill Angkor Wat or Machu Picchu.

Myanmar is still finding itself after decades of civil war and international isolation. The current crisis over the country’s treatment of the Rohingya Muslim minority is also attracting global criticism.

None of which makes this 11th-century temple city anything less than more magical.

The kingdom that reigned here was destroyed by earthquakes and Kublai Khan’s invaders, but the quiet temples retain a spiritual air that’s impossible to ignore.

Tikal, Guatemala

Hidden in the jungles of Guatemala, Tikal was a Mayan citadel that reflects more than 1,000 years of cultural achievements beginning from 600 BC.

Jaguars and pumas prowl the surrounding wilderness, but the palaces, temples and plazas within the site represent some of the earliest pinnacles of human achievement.

The stepped pyramids are icons of Mayan culture that rise above the canopy.

Equally impressive are the sporting courts, temples and palaces that ring the main plaza.

Most of the ancient causeways that link Tikal’s 3,000 structures have been cleared of vegetation, so visitors can now wander among the buildings much as the ancients did.

Cairo, Egypt

For first-time visitors, it’s a shock just how close the pyramids of Giza and the Great Sphinx are to Cairo’s chaotic streets.

With 22 million people, Cairo is one of the world’s biggest cities, built around one of humanity’s earliest urban centers.

Tombs at Giza date back 4,500 years, and the Egyptian Museum of Antiquities boasts an incredible collection from the Nile’s earliest inhabitants.

But the slightly less ancient parts of Cairo are also rich with cultural treasures.

The current city was founded more than 1,000 years ago and has one of the world’s oldest universities, a rich legacy of Islamic art, and Coptic treasures that are often overlooked.

Persopolis, Iran

Mohammad Reza Domiri Ganji
Mohammad Reza Domiri Ganji's amazing photos of Iran are a great introduction to some of the country's rich cultural attractions. Among them is this literary institute in Shiraz, which has a reputation as a city of great poets and poems.
Mohammad Reza Domiri Ganji
Located on the western edge of Isfahan's Naqsh-e Jahan square, this six-story palace's name means "grand doorway."
Mohammad Reza Domiri Ganji
The 18th-century Karim Khan castle stands in the center of Shiraz. "The unique architecture, lighting and patterns presented in the Iranian baths catches the eye at first glance," says Ganji.
Mohammad Reza Domiri Ganji
Built in 1971, the Azadi tower marks the 2,500th anniversary of the Persian Empire. "I like this tower for its unique architecture," says Ganji.
Mohammad Reza Domiri Ganji
Located in the north of Iran, this natural spring produces water rich in salts and sulfur. "It has a reflection of the sky that adds to its charm and beauty," says Ganji.
Mohammad Reza Domiri Ganji
This 19th-century carpet merchant's house in Kashan today serves as the base of the city's Cultural Heritage Organization.
Mohammad Reza Domiri Ganji
Carpet-making is one of the oldest and most important industries in Iran, says Ganji. "I tried to capture the spirit of life which exists in this workshop and its workers. Every carpet brought here to be repaired has a spirit too."
Mohammad Reza Domiri Ganji
The 18th-century Dolat Abad garden follows a classic Iranian design, and has a distinctive windcatcher -- a building used to provide natural air conditioning.
Mohammad Reza Domiri Ganji
"The exclusive ornaments of this building, such as the glasses, the mirrors, and tall columns are of exceptional beauty," says Ganji.
Mohammad Reza Domiri Ganji
Eram owes its fame and importance to the variety of unique and rare plants in its botanical gardens. "As I walked into the gardens, the first thing I noticed was the positive energy emanating from the place due to its green and colorful surroundings," Ganji says.
Mohammad Reza Domiri Ganji
Built for Qajar era Shiraz dignitary Forough-Al-Mulk, this three-story building now houses a museum.
Mohammad Reza Domiri Ganji
"When I entered the mosque I was amazed by the fantastic artwork in its ceiling," says Ganji. "It got my attention and when I saw that view, I wanted to photograph it."
Mohammad Reza Domiri Ganji
Located in the southwestern Iranian city of Julfa, this bath was originally used by royals of the Safavid dynasty and later opened to the public.
Mohammad Reza Domiri Ganji
This salt lake sits next to the Maranjab desert south of Tehran. It's actually a dried lake that only very occasionally collects water after heavy rain or snow.
Mohammad Reza Domiri Ganji
"This is taken on a regular day and shows what a desert is supposed to look like -- dry and hot white sands shining under the sunlight."
Mohammad Reza Domiri Ganji
"This shows a surprise view of the desert -- covered in snow," adds Ganji. "After hours of driving along a freezing snow-covered road, then hiking to reach the desert, I managed to photograph this rare moment just after sunrise."
Mohammad Reza Domiri Ganji
Another Qajar era treasure, this mosque has eastern and western bedchambers. "In fall and winter when sunlight shines through the glass, it casts the bedchamber in a beautiful light," says Ganji.
Mohammad Reza Domiri Ganji
In the decade before the Islamic revolution, this palace served as a residential home for the shah's family and was where they met foreign guests.
Mohammad Reza Domiri Ganji
Third-century Persian ruler Ardashir I -- the founder of Iran's Sassanid Empire -- built this palace for himself.
Mohammad Reza Domiri Ganji
"This is a very important monument, as it is relates to one of the most famous Persian emperors," says Ganji. "The Milky Way is only visible on certain summer evenings where the sky is clear and there's no moon."
Mohammad Reza Domiri Ganji
This tomb consists of a chamber with sloping roof built on seven stone tiers. In 336 BC, when Alexander the Great invaded Persia, Pasargadae was destroyed and the entire treasury of the palaces and tomb of Cyrus were looted.
Mohammad Reza Domiri Ganji
"I've always loved this historic complex because it's a reminder of one of the greatest empires of Iran and is part of our historic identity," says Ganji.
Mohammad Reza Domiri Ganji
"The ceiling of this place is like none other," says Ganji. "One of the most exquisite works of architecture, it's hard to look away."
Mohammad Reza Domiri Ganji
A highlight of Isfahan's Naqsh-e Jahan Square, this was built during the reign of Shah Abbas I.
Mohammad Reza Domiri Ganji
Another Safavid treasure, this place gained fame through a shrine built to Shah Ismail I's ancestor Sheikh Safi al-Din.
Mohammad Reza Domiri Ganji
This majestic structure, built under Shah Abbas I, takes its name from the archways which stretch across the water.
Mohammad Reza Domiri Ganji
"To photograph this bath I went there several times and sat on its couches for hours," says Ganji. "I tried to choose a time when artificial lights were off and the only source of illumination was the light from holes in the ceiling."
Mohammad Reza Domiri Ganji
"Because of its importance for non-Muslims in Iran, I've always wanted to take a photograph worthy of this building's status to add to my collection of my historical places in Iran," says Ganji.
Mohammad Reza Domiri Ganji
Built for a famous Kashan merchant during the Qajar dynasty era, this house has several sections decorated with different types of art and architectural features, such as stucco and stained glass.
Mohammad Reza Domiri Ganji
"All around there are shops selling rugs and historical artefacts, but the most amazing view here is this ceiling," says Ganji. "Under the ceiling there's a big pond, which I had to stand in to take this photo directly under the ceiling's center."
Mohammad Reza Domiri Ganji
"Contrary to appearances in this picture, this place is always very busy, particularly in the late afternoons and evenings. It's a popular site, with poets and poetry enthusiasts, groups of friends and young couples all coming together to recite Hafez's romantic poems."
Mohammad Reza Domiri Ganji
"The amazing symmetry of the architecture and its limestone embellishments make this bath one of a kind," says Ganji. "To capture this stretched panorama, I needed permits to allow me to stand in the middle of the deep bath."
Mohammad Reza Domiri Ganji
"I like this mosque because of the many pillars used inside," says Ganji. "As you enter, the repetition of these pillars makes the place grand and beautiful, and gives the impression of many separate spaces. In my photo I've tried to show this repetition in the best way."
Mohammad Reza Domiri Ganji
"I was amazed by the golden color of the ceiling and the unique paintings all around," says Ganji. "I put my camera on the floor and tilted it upwards using a wide lens to capture this photo."

Iran’s openness to Western tourism in recent years has helped Persepolis regain its allure for visitors, even if international relations have once more become strained.

The city was founded in 518 BC by Darius I, ruler of ancient Persia’s Achaemenian Empire, and grew in grandeur until Alexander the Great sacked it two centuries later.

Its most remarkable feature is an immense terrace of 125,000 square feet, partially carved out of Mount Kuh-e Rahmat (the Mountain of Mercy).

Rulers built ever more regal palaces, temples and halls around the terrace, complete with an underground sewage system and cisterns for fresh water.

Despite a series of protective walls, rising to 30 feet high, Alexander laid waste to Persepolis, whose ruins were only rediscovered in 1618.

Today, however, the city is one of the best examples of ancient architecture, especially for the slender columns that remain.

Kyoto, Japan

Buddhika Weerasinghe/Getty Images AsiaPac/Getty Images
Kyoto cool: Japan's former capital preserves old traditions.

If Tokyo represents the part of Japan obsessed with technology and the future, Kyoto is the part that rakes sand in Zen gardens and performs graceful tea ceremonies.

That’s not entirely fair – Nintendo is based in Kyoto, just one part of the city’s thriving tech scene.

Perhaps closer to the truth is that as imperial Japan’s capital for more than 1,000 years, Kyoto has found a way to respectfully preserve its old traditions while eagerly embracing the new as well.

More than 1,000 Buddhist temples and Shinto shrines temper the frenetic pace of modern life. Sites such as Nijo Castle, which dates back to 1603, draw people from around the world.

Since the city was largely spared bombing during World War II, most are still in use.

Beijing, China

01:20 - Source: CNN
A wintry tour of the Great Wall of China

China has invested heavily in eye-popping modern architecture for its capital over the last two decades, but with a past that stretches more than 3,000 years, the city has a deep history providing a rich legacy of art, architecture and education.

Just visiting the city’s six UNESCO World Heritage sites, including the Forbidden City and the Temple of Heaven, could take a week.

That would barely allow even a casual glance at the treasures inside the city’s legion museums and galleries, much less the alleyways of the hutongs, old neighborhoods reinvented and sometimes rebuilt as a trendy center of the Beijing’s modern life.

Great Zimbabwe, Zimbabwe

From the 11th century, this kingdom in southeastern Zimbabwe grew into a trading empire that stretched through the African interior and across the Indian Ocean.

A royal complex grew on a hilltop, with drystone architecture creating a terraced palace with fruit trees, hidden chambers and stunning views over the king’s dominion.

Below, the towering walls of the Great Enclosure surround a conical tower that’s become a national symbol.

Overpopulation and deforestation caused the kingdom’s collapse around 1450 – historically bad timing as Europeans soon began arriving to find a weakened polity that was easier to subdue.

Great Zimbabwe remains a monumental reminder of Africa’s achievements before colonialism.

Timbuktu, Mali

Before the Sahara nearly swallowed the city and before French colonialists swept through, Timbuktu was one of the world’s most important centers of learning.

The city’s librarians guarded thousands of manuscripts, protecting them against the elements and violence.

Many of the manuscripts were evacuated to Mali’s capital Bamako during the last period of separatist violence, but the city’s unique mosques remain.

The three most important ones date as far back as the 14th century.

Their earthen architecture requires continuous maintenance, and caretakers today use the same techniques to preserve them as the original builders.

Machu Picchu, Peru

AFP/Getty Images
One of the most popular ancient cities in the world.

Nearly 8,000 feet high in the Andes, the Incan citadel of Machu Picchu retains an aura of mystery and majesty even as it welcomes thousands of tourists a day.

When the Spanish conquered Peru, Machu Picchu’s very existence was kept secret from them.

The vast complex was revealed to the outside world in 1911, and quickly became the emblem of Incan achievement.

Built more than 500 years ago with drystone construction, the city sits on the saddle between two peaks rising above tropical jungles.

Clouds swirl among the ruins, whose significance remains largely unknown.

Terraces and ramps skirt the mountains, and the buildings appear to reflect the Inca’s sophisticated grasp of astronomy – though archeologists are still seeking to understand exactly how.

Athens, Greece

Athens traces its origins back 5,000 years, but the modern city has found remarkable ways to coexist with its iconic ancient monuments.

Below the Acropolis, walkable neighborhood streets wind past cafes and shops.

Many brim with tourist tchotchkes, but with enough art galleries and good eating mixed among them even the most jaded traveler will be satisfied.

Much of the city’s social life centers around the monuments, turning the stunning ruins of classical Greece into casual backdrops of Athenians’ every day lives.

Petra, Jordan

02:52 - Source: CNN
Growing up with Petra, Jordan, as a playground

This region between the Dead Sea and the Red Sea has been inhabited since the earliest days of humanity, but around 300 BC the rulers of the Nabatean Kingdom laid their claim to cultural greatness by carving magnificent buildings into red sandstone cliffs.

Gorges and canyons surround the ancient city, creating a maze of passages that helped keep it secret from Europeans for centuries.

Adding to the mystique: no cars are allowed in the ancient city.

Visitors who don’t want to walk have to hire a camel, donkey or carriage to get around.

Ellora, India

Like Petra, Ellora was carved out of the mountains in the area of Maharashtra. But this Indian monastic complex remains relatively unknown.

The temples include Hindu, Buddhist and Jaina holy sites that were built over 400 years, beginning in the 6th century.

The most impressive has the uninspiring official name of Cave 16, known informally as Kailasa, and the entire temple was carved out of a massive rock face.

The double-story entrance leads to a courtyard surrounded by a three-story arcade lined with columns. The building is twice as large as the Parthenon.

Inside, images of Hindu deities were sculpted from the stone, with two life-size statues of elephants in the courtyard.

Xi’an, China

Shen Lu/CNN
In addition to the famed Terracotta Warriors, Xian's well-preserved city wall is worth a visit.

In the Silk Road’s heyday, Xi’an was where the journey west began.

For more than a millennium, Xi’an was the capital of ancient Chinese dynasties.

Now it’s most famous as the home of the Terracotta Warriors – thousands of clay soldiers that fill the mausoleum of Emperor Qin Shi Huang. Each is standing, ready for battle, but they had been buried underground for 2,000 years.

Workers digging a well stumbled upon one of the soldiers in 1974, leading to one of the great archeological finds of all time.

Excavation is still underway, and more recent work has discovered statues of dancers and acrobats, giving a new sense of the grandeur of Qin’s ambitions.

Madurai, India

In ancient days, the Tamil city of Madurai was an important capital that traded with Rome and ruled over its part of India until the British conquest.

At its heart is the Meenakshi Amman Temple, one of India’s holiest sites that draws one million visitors for its annual festival in April and May.

Although the city is 2,500 years old, the original temple was sacked during a period of medieval invasions.

The current structure was built in the 1600s, with 14 gateway towers guarding the shrines covered in vibrant colors.

The Thousand Pillar Hall is carved with the mythological yali, a creature with the head of elephant on the body of a lion.

Poverty Point, Louisiana

Largely unknown even to Americans who live nearby, Poverty Point in Louisiana achieved the height of early human civilization in North America.

It’s named for a plantation located nearby, as the original name has been lost to time.

The city probably reached its greatest heights around 3,500 BC, when its people carved out six concentric, elliptical ridges from the earth.

They also built five large mounds, erected causeways and established docks that gave them easy access to the Mississippi River. That helped turn this site into a trade hub for a network that stretched over hundreds of miles.

Though the area was developed by people who hunted, fished and gathered wild plants for food, farming hadn’t been established yet.

Borobudur, Indonesia

Ulet Ifansasti/Getty Images AsiaPac/Getty Images
Borobudur is the most visited tourist attraction in Indonesia.

Foreigners tend to think Indonesian travel as centering on the tranquil island of Bali or the hectic capital Jakarta. But the most-visited site in this mainly Muslim nation is the ninth-century Buddhist temple complex of Borobudur.

The temple was completed in the early 800s, but much of its history has been lost.

For centuries, it lay covered under volcanic ash, and then the surrounding jungle grew over it.

In the early 1800s, locals told a British governor about its existence. In the 1970s, UNESCO guided a restoration that brought Borobudur to its current glory.

Now the stupas once again rise among the green valley. Because the complex was buried for so long, most of the artwork remains intact.

Takht-i-Bahi, Pakistan

This Buddhist monastery was built in the first century, but fell out of use a mere 600 years later.

Takht-i-Bahi’s location on a hilltop protected it against a succession of invasions, until the British came through and hauled off most of the surviving treasures to keep in the British Museum.

What remains are three stupas and the court surrounding them, as well as meditation chambers once used by monks who brought Tantric traditions to this part of the world.

In the popular imagination, Tantric practices revolve around sex.

Takht-i-Bahi is a reminder that Tantra is so much more.

Stonehenge, England

Archeologists believe this prehistoric stone circle could have been built as much as 5,000 years ago.

There’s general agreement that the area was a burial ground, but no one really understands how the giant stones were brought in from as far away as Wales.

Construction may have taken place over 1,500 years, at a time before the wheel had arrived in England.

Gondar, Ethiopia

The capital of the old Ethiopian Empire, Gondar suffered under repeated invasions from the mid-1800s. However, several castles and churches remain, offering a look into one of the few medieval African cities that’s still alive today.

Tourism here is not heavily developed, so wandering among these royal walls feels more like time travel.

The city is often called Africa’s Camelot, which seems unfair.

Gondar is the center of a culture that’s connected to the broader Christian world and completely distinct from it.

Nimrud, Iraq

The capital of the world’s first empire, Nimrud ruled over Assyria from around 880 BC, though humans settled the area thousands of years before.

Excavations since the 1840s revealed a formidable city with massive palaces and temples to gods of war and writing.

Ivory furniture, carved stone slabs, gold jewelry and crowns were all buried inside.

The art and architecture are irreplaceable, but many were destroyed in 2016 as Nimrud sits just outside Mosul.

After the Islamic State occupied the area, they brought in bulldozers to raze the ancient monuments. The extent of damage is still being assessed, but efforts are now underway to restore this ancient marvel.