MoonWalk London

Getting undressed in public isn't everybody's idea of a good time, but it sure is a great way to raise funds and awareness for breast cancer charity Walk the Walk, and this power walking marathon takes place overnight, which is a much less ostentatious time to take your top off than broad daylight. Thousands of participants will take on the 26.2 mile (or 13.1 mile Half Moon) route through London wearing decorated bras to raise money for charity, and this year the event celebrates its twentieth birthday with a carnival theme, so you can take your fancy dress that bit further should you feel so inclined. Register in advance. The routes start on Clapham Common.