Tower Bridge, London

The Tower Bridge is a bascule bridge that crosses the River Thames in London, England. It was completed in 1894 and the original hydraulic machinery still opens the bridge, although it has been modernised. The central span of 200 feet (61 m) between the towers is split into two equal bascules or leaves, which can be raised to an angle of 83 degrees to allow river traffic to pass. The high-level walkways between the towers houses an exhibition on the bridge's history.