THE MAYOR'S ThAMES FESTIVAL

The Mayor’s Thames Festival is a spectacular, free celebration of London and its river. Taking place over the middle weekend in September between Westminster Bridge and Tower Bridge, the festival brings Londoners together in the very heart of the capital to dance, make sculptures, listen to music, watch movies, drink, eat, enjoy performances, sing, play on the beach, sail on the Thames and dance in the streets.
Essentially, we want to provide a celebration for London and its river, a city centre party if you like, one that is free and open to all. We want to close roads and bridges and transform them with culture. We want to educate and transform people’s ideas about the river, too. Most of all, we want people not just to be spectators, but to be active participants in this spectacular London event.
The Mayor’s Thames Festival is an annual free event celebrating our city’s greatest natural asset, the River Thames. The Festival takes place right in the heart of London, between Westminster Bridge and Tower Bridge, on the river banks and on the adjacent riverside walkways and public open spaces.
The Festival commissions high-profile, cutting-edge arts events for unique environments on and around the river. It also showcases the best in street arts, with pyrotechnics, illuminations, art installations, river events, street theatre, massed choirs, circus and music.It has grown to become the capital’s largest free, open-air arts festival.
The 2008 Thames Festival will take place on the 13th and 14th September - 2008 marks the festival’s 10th Anniversary.

source: http://www.thamesfestival.org/cn/about/index.php