The main event was in Frankfurt, where Chancellor Angela Merkel, President Joachim Gauck and other leading public figures celebrated reunification while warning about the challenges Germany faces in the future.
Merkel and Gauck, Germany's two most senior political figures, both grew up in the German Democratic Republic (GDR) and both paid homage to the peaceful nature of the protests which brought about the end of communism in their speeches.
But not all was harmonious in Germany's finance capital. A crowd of around 50 left-wing demonstrators attempted to occupy the tent where members of the Bundesrat – Germany's upper legislative house – were gathering for the symbolic transfer of leadership of the house.
The protesters were demonstrating against what they see as Germany's reluctance to take in enough refugees.
In Berlin, tens of thousands poured onto the Straße des 17. Juni, which leads through the Tiergarten to the Brandenburg Gate and is named after the first popular uprising against the Communist regime, crushed by Soviet tanks in 1953.
At certain points the street needed to be closed to further visitors because of overcrowding.
Story continues below…
Pop stars and schlager singers performed at a concert in front of the Bundestag – the German parliament – and the celebrations were capped with a firework display which lit up the parliament – a building which lay derelict in no man's land during the Cold War.
SEE ALSO: How October 3rd became German Unity Day