Thames Barrier Information and Learning Centre

The striking, futuristic Thames Flood Barrier is designed to protect London from floods and surge tides until at least 2030. Each of its moveable gates is as tall as a five-storey building, and it's quite a sight when it's raised. The tiny visitor centre will fill you in on the science of daily tides, spring tides and surge tides that threaten the city.

With water levels rising by as much as 75cm a century as the river itself narrows, the barrier is increasingly necessary. Some 300 people were drowned in 1953 when the Thames burst its banks, and since the barrier was built it's saved London from another such catastrophe about 70 times. (In January 2003, a record was set when it had to be raised 14 times in the first week alone.)