Oscar Niemeyer, a towering figure in modern architecture who shaped the look of contemporary Brazil, has died, at the age of 104.
President of Brazil Dilma Rousseff paid tribute by calling him "a revolutionary, the mentor of a new architecture, beautiful, logical, and, as he himself defined it, inventive".
Mr Niemeyer's body will lie in state at the presidential palace.
Starting in the 1930s, Mr Niemeyer's career spanned nine decades.
His distinctive glass and white-concrete buildings include such landmarks as the UN Secretariat building in New York, the Communist Party headquarters in Paris and the Roman Catholic Cathedral in Brasilia.
Mr Niemeyer won the 1988 Pritzker Architecture Prize, considered the Nobel Prize of Architecture, for the Brasilia cathedral.
Its Crown of Thorns cupola fills the church with light and a sense of soaring grandeur even though most of the building is underground.
It was one of dozens of public structures he designed for Brazil's made-to-order capital, a city that helped define "space-age" style.
After flying over Mr Niemeyer's pod-like Congress, futuristic presidential palace and modular ministries in 1961, Russian cosmonaut Yuri Gagarin, the first man in space, said "the impression was like arriving on another planet".
The collection of government buildings in Brasilia remains his most monumental and enduring achievement. Built from scratch in a wild and nearly uninhabited part of Brazil's remote central plateau in just four years, it opened in 1960.
While the airplane-shaped city was planned and laid out by his friend Lucio Costa, Mr Niemeyer designed nearly every important government building in the city.
An ardent communist who continued working from his Copacabana beach penthouse apartment in Rio until days before his death, Mr Niemeyer became a national icon.
Despite years of bohemian living, he remained married for 76 years to Annita Baldo, his first wife.
He married his second wife, long-time aide Vera Lucia Cabreira, in 2006 at the age of 99. She survives him, as do four grandchildren.
Mr Niemeyer's only daughter, an architect, designer and gallery owner, Anna Maria, died on 6 June at the age of 82.