To mark the 800th anniversary of the famous London Bridge, the Royal Institute of British Architects has launched a competition for designs of an inhabited bridge.The current London Bridge is not the Victorian Gothic Tower Bridge, as many people believe, but a rather bland stone one. Its predecessor was also uninteresting and was bought by mistake and put in the Arizona desert. But the original London Bridge was a cultural icon, a bridge covered in buildings.Inspired by the competition we have put together a list of the most interesting inhabited bridges, from surreal single house bridge designs to Zaha Hadids sleek Zaragoza Expo bridge .