Tokyo Yamathon

For keen walkers and inquisitive visitors alike, the Yamathon tramps through parts of Tokyo other walks just don't reach. This fundraiser sees teams of four people (max) follow the circular Yamanote line, a hike undertaken to raise cash for Oxfam Japan. The event is open to all comers, though you'll need to be sprightly enough to complete the course in under 12 hours. The deadline for registrations is November 7.