Germany has been marking 30 years since the Berlin Wall was brought down, an event which heralded the end of Communism in Eastern Europe.
A ceremony was held to mark the anniversary at Bernauer Strasse – where one of the last parts of the wall remains – which was attended by leaders from Germany, Poland, Hungary, Slovakia and the Czech Republic.
Afterwards they placed roses in gaps in the barrier that divided the city for 28 years.
Speaking at a memorial service in a small chapel near where the wall once stood, Mrs Merkel commemorated those who were killed or imprisoned for trying to flee from East to West Germany and insisted that the fight for freedom worldwide is not over.
She said: "The Berlin Wall, ladies and gentlemen, is history and it teaches us no wall that keeps people out and restricts freedom is so high or so wide that it can't be broken down."
She also recalled that 9 November remains a fraught date in German history because it also marks the anniversary of the so-called Night of Broken Glass, an anti-Jewish pogrom in 1938 that foreshadowed the Nazis' Holocaust.
Head of the Berlin Wall memorial site, Axel Klausmeier, recalled the images of delirious Berliners from East and West crying tears of joy as they hugged each other on the night of 9 November 1989.
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He paid tribute to the peaceful protesters in East Germany and neighbouring Warsaw Pact countries who took to the streets and demanded freedom and democracy.
He also praised the then-Soviet leader Mikhail Gorbachev's policy of reforms.
The country's Communist government was put under pressure to open its borders to the West by the protests and people fleeing East Germany.
Germany has become the most powerful economic and political force on the Continent since the wall fell, but there remains deep criticism in the country over how the transition from socialism to capitalism was managed.
This was acknowledged in a recent interview with German chancellor Angela Merkel who said that "with some things, where one might have thought that East and West would have aligned, one can see today that it might rather take half a century or more".
Concerts, light shows and public debates are planned throughout the city and other parts of Germany to mark the fall of the wall, including a concert at Berlin's iconic Brandenburg Gate.