The cycling road race at the 2012 London Olympics will start and finish in front of Buckingham Palace.

Organizers on Thursday unveiled the route, which will cut through central London before crossing the River Thames at Putney Bridge in Fulham and heading off on a loop of Surrey county.

The 250-kilometer (155-mile) men's race will be held on July 28, 2012, and feature 145 riders. The women's race, held the following day, will have 67 riders competing over a 140-kilometer (87-mile) course.

The route was changed from the one proposed in London's original Olympic bid. The circuit was originally intended to veer into north London, including Regent's Park, but will now feature a challenging circuit around Box Hill, south of London.

A test event in London is being planned for August 2011.