Rolling Bridge, Paddington Basin

The lowdown

At Paddington Basin sits one of Thomas Heatherwick's cleverest early works, the Rolling Bridge. Most of the time it is a simple steel-and-timber footbridge over the canal, but on a regular schedule it performs an extraordinary trick, slowly curling up segment by segment until it forms a neat octagonal ball on the bank, clearing the water for boats.

Watching it roll up and unfurl is mesmerising, a piece of engineering as theatre, and it costs nothing. It is one of several quirky bridges around the redeveloped basin, making the canalside a free and surprisingly fun detour right beside the station.