The flight of the glowing white orbs through the heart of Berlin marked the climax of a huge open-air party at the Brandenburg Gate, the symbol of German unity, which drew an estimated one million guests to the city.
A quarter-century after the breach of Europe's Cold War division, artists had tethered nearly 7,000 balloons along a 15-kilometre (nine-mile) stretch of the despised concrete barrier's former 155-kilometre path, making it visible once again.
As the balloons were released and floated to the heavens, the Berlin State Orchestra, under the baton of Daniel Barenboim, played Beethoven's "Ode to Joy".
Earlier, British singer Peter Gabriel sang a stripped-down version of David Bowie's Wall anthem "Heroes", sharing the stage with rock bands from east and west Germany and former dissidents.
Fireworks followed the release of the balloons.
Merkel, 60, who grew up in communist East Germany, said earlier at a memorial for those killed trying to escape the repressive regime that the Wall was a "symbol of state abuse cast in concrete" that "broke" many people.
In an unusually emotional speech, Merkel said: "We can change things for the better - that is the message of the fall of the Berlin Wall."
This is true for Germany and "for the people in Ukraine, Syria, Iraq and in many, many other regions of the world where liberty and human rights are threatened or being trampled," she said.
'Dreams can come true'
Merkel said the events inspired hope that the world can tear down "walls of dictatorship, violence, ideology and hostility".
"Too good to be true? A daydream that will burst like a bubble? No, the fall of the Wall has shown us that dreams can come true."
The celebrations started on a sombre note with an ecumenical service and ceremony for the at least 389 victims of the border, many of whom were shot or blown up by mines as they tried to flee the East.
A couple from the former West Berlin, Gunnar and Uschi Schultz, who visited the memorial early Sunday, recalled how they spent the entire historic night in 1989 at the Brandenburg Gate, which was a centrepiece of the tense frontier for 28 years.
"It was wonderful, obviously, wonderful, but at the same time, strange," said medical researcher Uschi, 50, about the night when citizens from both sides found the courage to cross into the heavily guarded no-man's land.
"The police were very hesitant. It's a miracle that no shot was fired."
Frank Marschner, a 56-year-old forester from the east German town of Neustadt, said November 9th, 1989 marked the beginning of a new chapter in his life.
"The freedom to travel is the freedom we've enjoyed the most," he said, joined by his wife Pia, 54.
"It started with a jaunt to West Berlin and it's since taken us to Canada, Greece, Cape Verde - all over the world. Places we could never even dream of in the GDR," he added, using the acronym for communist East Germany.
Unlike for the 20th anniversary, when foreign heads of state and government flocked to Berlin, the festivities this year were mainly a people's celebration in a city that has blossomed into an international cultural hub and major tourist destination.
The only foreign dignitaries were veterans of the era, chiefly the last Soviet leader, Mikhail Gorbachev, 83, whose "glasnost" and "perestroika" reforms kicked off the series of historic events.
Gorbachev, who remains highly popular in Germany, warned at a Wall commemoration on Saturday that the world was on the "brink of a new Cold War", amid East-West tensions over Ukraine.
Also at the festivities were Polish freedom icon Lech Walesa, 71, Hungarian ex-premier Miklos Nemeth, 66, and German President Joachim Gauck, 74, a former Christian pastor and rights activist in the East.
Pope Francis also honoured the events of 25 years ago, noting that people were "killed for their beliefs or religion".
"We need bridges, not walls," he said from the Vatican.
East Germany built the Wall, which it called an "Anti-Fascist Protection Rampart", in August 1961 to halt a mass exodus of its citizens to the West.
On November 9th, 1989, East German border guards, overwhelmed by large crowds after months of mounting protests against the regime, threw open the gates to West Berlin, allowing free passage for the first time since it was built.
Germany would reunite within the year, on October 3rd, 1990.