Rolling Bridge.

This awesome rolling bridge is made by Heatherwick Studio and is located in Paddington Basin, London, UK:

Rather than a conventional opening bridge mechanism, consisting of a single rigid element that lifts to let boats pass, the Rolling Bridge gets out of the way by curling up until its two ends touch. While in its horizontal position, the bridge is a normal, inconspicuous steel and timber footbridge; fully open, it forms a circle on one bank of the water that bears little resemblance to its former self.

Twelve metres long, the bridge is made in eight steel and timber sections, and is made to curl by hydraulic rams set into the handrail between each section.

Link - via Appelogen