(CNN) European leaders gathered in Berlin on Saturday to mark 30 years since the fall of the wall that divided East and West Berlin, where German Chancellor Angela Merkel urged Europe to defend democracy and freedom.
Leaders from Central and Eastern Europe gathered in the German capital to celebrate the pivotal moment in history that marked the end of communism and the reunification of the country.
German Chancellor Angela Merkel and others place flowers at the Wall Memorial.
A number of events took place across the city, which included the commemoration ceremony at the Berlin Wall Memorial that leaders attended.
During the commemoration, Merkel said European values must not be taken for granted.
"The values that Europe is based on -- freedom, democracy, equality, rule of law, human rights -- these are not to be taken for granted," Merkel said. "We always have to defend them.
"In the future Europe will [continue to] be fighting for human rights, tolerance and democracy." she added. "This is a time of global changes, so this is a pressing issue."
German Chancellor Angela Merkel greets young visitors as she walks to the Chapel of Reconciliation before attending the memorial service.
Candles were also being lit for victims of communist violence and celebrations continued into the evening at the Brandenburg Gate -- the symbol of a reunified Germany which once stood at the center of the no man's land between East and West.
The seismic event of the fall of the Berlin wall sent shock waves across Europe 30 years ago, and sparked hopes for millions of East Germans.
On August 13, 1961, citizens woke up to find a makeshift barricade of barbed wire and cinder blocks that sliced through their city.
The rise and fall of the Berlin Wall
West German children interact with East German border guards after the fall of the Berlin Wall in 1989.
East German workers embed broken glass in the top of the Berlin Wall on August 22, 1961, shortly after construction began.
East German border guard Conrad Schumann's August 1961 escape over what was then a simple barbed wire barrier became one of the most memorable images of the Cold War era.
West Berliners wave at relatives in the East, September 1961.
Soviet and American tanks face off at the border crossing known as "Checkpoint Charlie," in October 1961.
East German bricklayer Peter Fechter, 18, is carried away by border guards after being shot and fatally wounded while attempting to flee to the West in August, 1962.
Almost 200 people were killed attempting to cross the Wall between 1961 and 1989.
A guard from West Berlin (right) talks to an East Berliner through a hole in the Wall, September 1962.
Martin Luther King Jr. gave sermons in both East and West Berlin during his September 1964 visit to the city. He won the Nobel Peace Prize later the same year.
Checkpoints along the Berlin Wall were temporarily opened in late March and early April 1972, to allow families and friends on both sides of the barrier to reunite over the Easter holidays.
Canadian-American peace activist John Runnings, then aged 68, walked along a section of the Wall in 1986, as a form of non-violent protest.
United States President Ronald Reagan delivers his famous speech in front of the Brandenburg Gate in 1987, urging his Soviet counterpart: "Mr. Gorbachev, tear down this wall!'
Hungarian border guards begin dismantling the "Iron Curtain" in May 1989, opening the country's border with Austria.
East German citizens scale the walls of the West German embassy in Prague in October 1989, in a desperate first step to freedom.
Protesters carry a banner reading "Gorbi Gorbi help us!" during a visit to East Germany by Mikhail Gorbachev -- then leader of the Soviet Union -- in October 1989.
Thousands of anti-Communist protesters hit the streets of Leipzig, East Germany, in November 1989. The massive protests were part of the peaceful revolution that helped bring down the Wall.
On November 9, 1989, the East German government opened the country's borders with West Germany. The following day, citizens tried to pull down the Wall with just about any tool they could get their hands on.
People walk on the Berlin Wall in front of the Brandenburg Gate on November 10, 1989.
East German border guards appear in a gap in the Wall after demonstrators pulled down a segment of the barrier, on November 11, 1989.
Thousands of people pass through a checkpoint at Bernauer Strasse, Berlin, on November 12, 1989.
A line of East Germany's famous Trabant cars heads West along a highway near Leipzig, following the fall of the Wall.
East German border guards peer through the damaged wall, near Checkpoint Charlie, in February 1990.
People walk along the longest remaining section of the Wall, now known as the East Side Gallery, in August this year.
A graffiti-covered, overgrown segment of the original Berlin Wall, pictured in September 2019.
The barrier evolved over the next three decades into a 45-kilometer concrete wall, which symbolized the deep ideological divide between the Soviet bloc and the West at the height of the Cold War. The three-and-a-half meter deep wall was fortified with watchtowers, electric fences and armed guards.
On November 9 in 1989, jubilant crowds stormed the concrete blockade, just minutes after the Communist German Democratic Republic (GDR) announced that travel restrictions would be lifted for east Germans. The propaganda and fear were replaced with a sense of freedom and unity.
However, despite the fall of the wall, three decades later an invisible barrier still stretches across Germany.
While slowly disintegrating, the divide remains. According to Steffen Mau, a sociology professor at Berlin's Humboldt University many gaps, particularly the economic ones have narrowed but people still have "strong differences in attitudes and mentality."
Even the way people see themselves and their country varies. Mau explains that most west Germans say there is "no difference any more ... while most east Germans would say there is still a striking difference between East and West."
According to some surveys, he added, as many as half of east Germans still feel like "second-class citizens."
In terms of wealth, the six eastern states had a lot of catching up to do when the Wall came down. And while a big chunk of that gap has closed over the past three decades, the East is still lagging behind, in terms of both GDP and incomes.
CNN's Ivana Kottasová and Radina Gigova contributed reporting.