The Prudential RideLondon-Surrey 100 is the largest sportive in the UK with thousands riding to raise money for charity. In 2016, more than 25,000 amateur cyclists took on the 100-mile (160km) challenge, which departs from Queen Elizabeth Olympic Park in the early hours of the morning.
The event is free to watch, and the route passes some of London's most famous landmarks as it heads out to the Surrey Hills, before returning to the capital with a magnificent finish on The Mall in front of Buckingham Palace.
Entry is by ballot, which is now closed, but charity places may still be available.
Find out what else is on during Prudential RideLondon 2017.