Frontiers in east Europe once guarded by machineguns and barbed wire in the Cold War fell away today as nine mostly former communist states joined the EU's border-free zone amid fireworks, cheers and music.
German Chancellor Angela Merkel, herself from ex-communist East Germany, hailed as historic a move seen by many as a final lifting of the old Iron Curtain.
From midnight, the nine joined 15 existing members to create an area one third the size of the United States, allowing passport-free travel for 4,000 km (2,500 miles) from Estonia to Portugal.
The extension of the European Union's so-called Schengen zone brought in Poland, Slovakia, Hungary, the Czech Republic, Slovenia, Malta, Latvia, Lithuania and Estonia.
The move is expected to boost business and tourism, though some worry about a rise in crime or illegal immigration.
Border posts were ceremonially lifted or cut, border guards left their booths and people walked freely across frontiers that once divided the former Soviet bloc from the West.
"We are very pleased to be able to experience this genuinely historic moment," Merkel said at a ceremony in Zittau on the German border with Poland, noting the borders had caused much suffering in the past.
New Polish Prime Minister Donald Tusk said the new measure was heart-warming.
People at border posts the length and breadth of eastern Europe celebrated with fireworks, cheers and music from midnight as the European Union's so-called Schengen zone was expanded.
In the German town of Frankfurt on Oder on the Polish border, one of the most politically significant frontiers in Europe with a past of war, about 2,000 people celebrated with the EU 's anthem, Beethoven's "Ode to Joy", and fireworks.
Frontiers also fell away between the Baltic states, including Latvian-Estonian Valga-Valka where a main street had been split by a border. At the Slovak-Austrian Petrzalka/Bergen crossing, people got souvenir stamps in their passports.