1. Brush up your tennis technique before Wimbledon at Bush Hill Park in Enfield which has ten free tennis courts, making it one of the largest free tennis centres in London. In general you can simply turn up and play, with no booking or payment required, although courts are sometimes used for coaching sessions and by local tennis leagues, so it’s advisable to check.
Bush Hill Park, Lincoln Rd, Enfield, EN1 1PS (tennisforfree.com, Bush Hill Park rail).
2. Take to the water at the Docklands Sailing & Watersports Centre at the west end of Millwall Outer Dock, in the heart of London’s Docklands. The award-winning, purpose-built facility is a Royal Yachting Association recognised training centre offering courses in sailing, windsurfing and power-boating, plus British Canoe Union approved courses in paddlesports.
Docklands Sailing & Watersports Centre, 235a Westferry Rd, E14 3QS (020-7537 2626, dswc.org, South Quay DLR).