courtesy Metropolis Books
"It's as if nature has come back into the city" was how Daniel Libeskind described his idea for a residential tower grafted onto New York's Credit Suisse headquarters. Nine hundred feet high -- 300 feet taller than the Met Life clock tower -- its living spaces were to have been complimented with an extensive sky garden, with sections open to the elements via cutaways. The spiraling structure sacrificed living space for urban greening and impressed key figures in the city. However when the subprime mortgage crisis of 2007 landed, it hit financier Credit Suisse, and once pictures of the secret design leaked, the embryonic project died an early death when faced with harsh economic realities.
courtesy Metropolis Books
Frank Gehry's Guggenheim Bilbao could have had an East River sibling, with four times the exhibition space as Frank Lloyd Wright's Fifth Avenue landmark.

With land pledged by then New York mayor Rudolph Giuliani and capital to bring the $678-million project to fruition, everything looked set. Then 9/11 happened. The global economy stuttered, and Gehry's vision of twisted steel was now imbued with harrowing connotations. In December 2002, the museum released a statement explaining that the design was being shelved and projects "on a more modest level" would be considered. And that was the end of that.
courtesy Metropolis Books
We all know what New York's skyline looks like. But there are countless other versions that never left the architect's drawing board. The new book "Never Built New York" brings together these flights of fancy to paint an alternative reality of the US' defining city.

Pictured: Rooftop Airport, William Zeckendorf (1945) -- The US had only just seen the back of World War II when realtor William Zeckendorf's ambitious design was mooted in December 1945. You could argue it wasn't the best climate to introduce a plan for a $3-billion elevated airport off Manhattan. The 144-sqaure-block, 200-foot expanse would have stretched from 24th to 71st street along the Hudson River, and would've had the same transport capacity as LaGuardia.

Among its futuristic touches, airplanes would ascend to the runway by elevator, and beneath would be a self-contained city, including factories, commercial spaces and apartments -- as well as docks, railroads and steamship terminals.
Alas, Zeckendorf's prediction that park commissioner Robert Moses and the City Planning Commission would denounce the project proved true. Looking over the plans Moses branded it "ridiculous," and the realtor's grand design went no further.
courtesy Metropolis Books
In an alternative universe, this would have been boat-bound immigrants' first taste of New York, not Lady Liberty. Featuring a 129 feet high figure on a 50-foot plinth, the National American Indian Memorial was at one stage described as "veritably the Eighth Wonder of the World" in a pamphlet at the time.

In the end, the monument, drawn up by Thomas Hastings, resembled the New York Public Library (which Hastings also designed). The monument had congressional approval and high-profile backers in Theodore Roosevelt and J.P. Morgan -- President William Howard Taft even broke ground in 1913 alongside Native American chiefs. But primary backer John Wanamaker soured relations with the indigenous communities soon after with an ill-conceived attempt to formally bring them into allegiance with the United States. Wanamaker, a heir not without his hobbies, lost interest and pursued his passion for flying boats, and when World War I came knocking, no one was in the mood to pick up the project once more.
courtesy Metropolis Books
Stadiums with roofs might be commonplace in the US in our day and age, but Geddes and Fuller's radical proposal in the mid '50s would have been a game changer.

Dodgers owner Walter O'Malley enlisted Fuller's skills in geodesic domes to create what would have been a 750 feet wide and 300 feet high fiberglass lid for the baseball team's new hi-tech stadium in Atlantic Yards, downtown Brooklyn. The roof would have retracted, with the whole structure containing channels to maintain air flow. On the ground would have been "a synthetic substance to replace grass on the entire field and (could) be painted any color" -- essentially AstroTurf, 18 years before it was invented.

Dodgers fans don't need to be told that their team eventually ended up in sunnier climbs: O'Malley took the club to Los Angeles, with questions over financing and delays making the Brooklyn project unworkable.
courtesy Metropolis Books
Fuller's attempt to shield a portion of Manhattan from the elements originated in July 1950 with an idea for a half-mile wide geodesic dome he called "Noah's Ark #2." Fuller thought that among the benefits of these would be the need to clear snow and ice from roadways and regulating extreme temperatures within.

"Future cities may have all housed activity -- dwelling, commercial and administrative -- within the dome shell, reserving whole interior of dome for a tropically gardened public park and community building area," wrote Fuller, who anticipated ascending roadways and high-speed vertical transport links to boot. Smaller scale versions proved structurally feasible, but 50 years on Manhattan has yet to greenlight the idea.
courtesy Metropolis Books
When Major League Soccer (MLS) commissioned SHoP for a stadium design in Flushing Meadows Park, they can't have realized the furore it would create. The 25,000-seat, $300-million stadium featured a wall-less structure with perforations in the facade, which would shield fans from the elements while offering views of the World's Fair Unisphere, located just to the west.

It was intended as the home of future MLS franchise New York City Football Club, but the design fell afoul of park advocates, who argued it rode roughshod over the area. The press picked up on negativity, but it was the New York Yankees (part owners of the franchise) who really buried the design, when they called for the soccer field to be built near Yankee Stadium in the Bronx. That plan was vetoed by Mayor Bill de Blasio, meaning the soccer team is currently playing in the football ground, and Flushing Stadium remains on the drawing board.
courtesy Metropolis Books
Previously known as Blackwell's Island, and today known as Roosevelt Island, the 147-acre strip between Manhattan and Queens was once dubbed Welfare Island. Largely unheralded, it contained hospitals, a few tenements and abandoned buildings.

Gruen had other plans: namely a $450-million megaproject involving eight- to 50-story apartment towers with room for 70,000 people. All of this was to be built on a 22-foot platform containing schools, shops and recreational space. Residents would be able to get around via moving sidewalks, but the project came to a halt when concerns were raised about transport links to the rest of New York City. Gruen had factored in ferries and helicopters to move his middle income inhabitants around the city, but that wasn't enough for new mayor John Lindsay, who called for fewer residences and larger green spaces.

In the end authorities approved a different plan including low-profile housing for 16,000 people and none of the social hubs (or pizazz) Gruen envisaged.
courtesy Metropolis Books
In October 2012 it was announced that Foster + Partners had won a star-studded competition with their design for 425 Park Avenue, New York City. But that commission only tells part of the story. Zaha Hadid's concept for the space never got past the illustration phase, existing in a state Daniel Libeskind describes as "oblivious to time." It's light, open design wasn't dissimilar to Foster + Partner's winning design, though Hadid's comes with her signature curves and extruded forms.
courtesy Metropolis Books
OMA also lost out to the British architecture firm. Its concertinaed monolith may not be physically built, but Libeskind suggests works like it may have untold influence over the future of architecture.

Editor’s Note: Daniel Libeskind is an architect, joint founder of Studio Daniel Libeskind and was CNN Style’s first guest editor in July 2015. Below is his foreword to new book “Never Built New York.”

CNN  — 

Architecture has always begun with drawing. Music, as we know, begins with a score. In this manner, both architecture and music have completed a work. Architectural drawings and musical scores live a life of perfect solitude even if in a drawer or an attic. Their future is yet to come.

Strangely enough, people cannot conceive of architecture or music without a physical performance.

One can build a building, and yet wind up without any architecture. One can make architecture in a drawing, yet never get to build. A composer may write a score, which may never be performed, but its lack of being performed does not disqualify it as a piece of music.

Herein lies the paradox of unbuilt and unperformed works. They live their own existence, oblivious to time. The power of a drawing and its creative force does not lie merely in its use as a tool for practical purposes. It lies in the beholder’s imagination.

Blackstation/courtesy gensler
Standing at 2,074 feet (632 meters) tall, the Shanghai Tower is the world's second tallest building.
via SL Green Realty Corp
A new tall tower has broken ground in New York City. Named the One Vanderbilt Avenue tower, the building is designed by Kohn Pedersen Fox architects, and construction officially started today. At 1,401 feet tall, upon completion it will be the second tallest building in New York after the One World Trade Center.

Height: 427m (1,401ft)
Architect: Kohn Pedersen Fox
image courtes of emaar / via aurecon group
A new megatall skyscraper will dominate the Dubai skyline. Currently unnamed -- 'The Tower', as it's being referred to by its developers for now -- will be built on the Dubai Creek Harbour, and will be 100m taller than Dubai's Burj Khalifa -- a skyscraper that is currently the tallest building in the world. Megatall buildings are defined by the Council on Tall Buildings and Urban Habitat (CTBUH) as a builidng over 600 meters (1,968 feet) in height.
Height: 928m (3,044ft)
Architect: Santiago Calatrava
image courtes of emaar / via aurecon group
The expected completion date for the structure is 2020.

Height: 928m (3,044ft)
Architect: Santiago Calatrava
image courtes of emaar / via aurecon group
The building will hold ten observation decks in its oval-shaped peak. One deck will offer a 360-degree view of the city.

Height: 928m (3,044ft)
Architect: Santiago Calatrava
istockphoto
Currently world's tallest building, since it was completed in 2010, is the Burj Khalifa. It stands a massive 198 meters (650 feet) above its nearest competitor.

Height: 828m (2717ft)
Floors: 163
Architect: Skidmore, Owings & Merrill
Jeddah Economic Company/Adrian Smith + Gordon Gill Architecture
Another threat to the Burj Khalifa's tallest building title is the Jeddah Tower in Saudi Arabia. The tower is currently under construction and due to top out at 1,000 meters at a cost of $1.23 billion.

Height: 3,280ft
Architect: Adrian Smith + Gordon Gill Architecture
In Feburary, a proposal for a mile-high tower in Tokyo was revealed.
Height: 1,600m (5,250ft)
Architect: Kohn Pefersen Fox Associates and Leslie E Robertson Associates
Kohn Pedersen Fox
The 1,600 meter tower is part of a future city concept named "Next Tokyo 2045," which envisions a floating mega-city in Tokyo Bay.

Height: 1,600m (5,250ft)
Architect: Kohn Pefersen Fox Associates and Leslie E Robertson Associates
DBOX
In December 2015, plans were unveiled for the 1 Undershaft -- a 300m tall building that could become the City of London's tallest building.
Height: 300m (984ft)
Floors: 73
Architect: Aroland Holdings
DBOX
1 Undershaft will sit across the river from London's tallest building, The Shard, which is 9.6 meters taller.

Height: 300m (984ft)
Floors: 73
Architect: Aroland Holdings
Courtesy CIM Group
432 Park Avenue, the tallest all-residential tower in the western hemisphere, opened its doors in December 2015, recently became the hundredth supertall building in the world.

Height: 425.5m (1396ft)
Floors: 85
Architect: Rafael Vinoly, SLCE Architects, LLP
Gensler

Completed in 2015, Asia's tallest building surpasses the Shanghai World Financial Center and the Jin Mao Tower in Shanghai's Pudong district. Estimated to cost $2.4 billion, its completion marked the end of a project in the financial district stretching back to 1993.

Height: 632m (2073ft)
Floors: 128
Architect: Jun Xia, Gensler
FAYEZ NURELDINE/AFP/AFP/Getty Images
Situated close to the Grand Mosque of the holy city of Mecca, the tower complex is one part of the $15 billion King Abdulaziz Endowment Project, seeking to modernize Mecca and accommodate the ever-growing number of pilgrims.

Height: 601m (1972ft)
Floors: 120
Architect: Dar Al-Handasah Architects
STAN HONDA/AFP/AFP/Getty Images
Known as the "Freedom Tower," One World Trade Center stands on part of the site previously occupied by the Twin Towers. It's the highest building in the western hemisphere, and cost $3.9 billion according to Forbes.

Height: 541.3m (1776 ft)
Floors: 94
Architect: Skidmore, Owings & Merrill
Taiwan Tourism
The first skyscraper to break the half-kilometer mark, the world's tallest building between March 2004 and March 2010 is also one of the greenest -- certified LEED platinum in 2011. Designed to withstand the elements, including typhoons, earthquakes and 216 km/h winds, Taipei 101 utilizes a 660-tonne mass damper ball suspended from the 92nd floor, which sways to offset the movement of the building.

Height: 508m (1667ft)
Floors: 101
Architect: C.Y. Lee & Partners
ChinaFotoPress/Getty Image
Construction of Shanghai's third supertall building took 11 years, but the skyscraper dubbed "The Bottle Opener" was met with critical praise and high-end residents when it completed in 2008, including the Park Hyatt Shanghai and offices for Ernst & Young, Morgan Stanley, and BNP Paribas.

Height: 492m (1614.17ft)
Floors: 101
Architect: Kohn Pederson Fox
ANTHONY WALLACE/AFP/AFP/Getty Images
Hong Kong's tallest building has 108 floors -- but walking around it, you'd get a different story. The city's tetraphobia -- the fear of the number four -- means floors with the number have been skipped, and the International Commerce Center is marketed as a 118-story skyscraper.

Height: 484m (1588ft)
Floors: 108
Architect: Kohn Pedersen Fox
Goh Seng Chong/Bloomberg via Getty Images
The joint eighth highest completed skyscraper is still the tallest twin towers in the world. Finished in 1996 and inaugurated in 1999, it's been the site of numerous hair-raising stunts. Felix Baumgartner set a then-BASE jump world record in 1999 by jumping off a window cleaning crane, and in 2009 Frenchman Alain Robert, known as "Spiderman," freeclimbed to the top of Tower Two without safety equipment -- and did so in under two hours.

Height: 451.9m (1483ft)
Floors: 88
Architect: Cesar Pelli
Sun Chen
The architects behind the Burj Khalifa are also responsible for the world's tenth tallest building. Skidmore, Owings & Merrill's Zifeng Tower in Nanjing completed in January 2010 and sits just above the Willis Tower (previously the Sears Tower) in the rankings, eclipsing the SOM-designed Chicago icon by a mere 7.9 meters (26 ft).

Height: 450m (1476ft)
Floors: 66
Architect: Skidmore, Owings & Merrill
Teddy Cross
Completed in March 2016, the Lotte World Tower is Seoul's first supertall skyscraper, and is currently the sixth tallest building in the world.

Height: 556 meters (1824 feet)
Architect: Kohn Pedersen Fox Associates
Wong Tung & Partners
A hotel and office hybrid, this straightforward supertall building by Wong Tung & Partners in Hunan Province's booming capital city is expected to be completed by 2017.

Height: 452 metres (1,482 ft)
Architect: Wong Tung & Partners
E8xE8
The Suzhou IFS is two meters shy of the Changsha tower.
Height: 450 meters (1476 feet)
Architect: Kohn Pedersen Fox Associates
Pei Cobb Freed & Partners
The World One skyscraper in Mumbai will be as tall as the Willis Tower, the second tallest building in North America, and will be one of the world's tallest residential structures.

Height: 442 meters (1450 feet)
Architect: Pei Cobb Freed & Partners
DLN Architects
This design mimics and simplifies the neo-Gothic spires of an earlier skyscraper boom, à la the Woolworth and Empire State Buildings.
Height: 383 meters (1,257 ft)
Architect: Dennis Lau & Ng Chun Man Architects & Engineers
Kohn Pedersen Fox Associates
Kohn Pedersen Fox is back with this 90-story residential building. Zigzagging cuts in the curtain-wall break up the monotony of yet another boxy tower.

Height: 372 metres (1,220 ft)
Architect: Kohn Pedersen Fox

A drawing might lodge itself in the mind and build itself to great heights within it. Beethoven composed his last works without physically hearing them played. He heard them in his mind; in his being.

So, too, architecture.

The contents of architectural drawings, be they realized or not, can enter the imagination of the public. Drawings thereby inscribe themselves as projects: future actions.

Just like music, an architectural drawing can wait a long time before revealing itself. Bach’s scores lay for some 200 years, unplayed and unperformed, until Mendelssohn rediscovered them and made them public through performance. Piranesi built only one building; Chernikhov built none – yet their creations are seminal to the history and production of architecture.

Architectural drawings have and will continue to act as a spur to the built world.

The drawings in this book, “Never Built New York,” are, for me, not a compendium of nostalgia, regret, or opportunities missed. They are, on the contrary, drawing the open mind to rethink the built and the unbuilt.

Never Built New York” is available via Metropolis Books.