Hungarian police have cleared a protest camp in a Budapest park where activists have been fighting to stop the destruction of 600 trees.
An alliance of green and civic groups wants to stop the project, aimed at creating a new museum district.
Critics say the scheme is designed to help Prime Minister Viktor Orban move the government to Buda Castle, now the site of the National Gallery.
But the government says the new district will boost tourism.
Ministers believe the new museum district, known as Liget Budapest, will also renovate the long-neglected park.
However, a recent opinion poll found that 80% of Budapest residents opposed the construction of new museums in the park.
Opponents argue that the project was drawn up without public discussion, overriding organisations representing Hungarian architects, which oppose the plans.
The Museum of Fine Arts, the Transport Museum and the City Zoo, all already in place, are to be rebuilt.
The National Gallery and the Ethnographic Museum, plus museums of photography, architecture and modern arts are to be relocated to the park from other parts of the city, while a new House of Hungarian Music is to be built on the site of the evacuated protest camp.
"I fail to understand what they are protesting about," Janos Lazar, minister in charge of the Prime Minister's Office, told reporters.
Begun in 1836 on former marshland, the park is one of the oldest in Europe.
According to the project website: "Liget Budapest will be one of Budapest's leading, well-known tourist and cultural destinations and a unique family park recognised as such all over Europe."