The Thames Barrier is a flood control device constructed across the river near Woolwich. The barrier was built to combat the rising risk of floods in London caused by rising sea level. Construction was completed in 1982 (after eight years!) at a cost of £534m (about £1.5bn in today’s money). The barrier works by hydraulically rotating half-cylindrical gates out of the river bed.
A shot showing one of the Thames Barrier structures, Canary Wharf and the Millennium dome.