Greenwich + Docklands International Festival 

WHAT: A 10-day free festival of art, theatre and street performance, some of which has a scientific bent, that is expected to draw about 50,000 people to Greenwich.
WHEN: June 24-July 4.
DO IT BECAUSE: A sprawling, well-organised street festival is a vital part of summer in London, and this one has more going for it than just cheap beer and lots of walking, with many of the spectacles exploring mind-bending scientific theories.

» Venues vary, but mostly in and around Greenwich Park and Maze Hill