River Thames Thames Estuary), the river is subject to tidal activity from the North Sea. Before the lock was installed, the river was tidal as far as Staines, about upstream. London, capital of Roman Britain, was established on two hills, now known as Cornhill and Ludgate Hill. These provided a firm base for a trading centre at the lowest possible point on the Thames. A river crossing was built at the site of London Bridge. London Bridge is now used as the basis for published tide tables giving the times of high tide. High tide reaches Putney about 30 minutes later than
Queen Elizabeth II Bridge, Newcastle upon Tyne two sections of the bridge were built simultaneously from each bank and eventually met in the centre in August 1978. It was officially opened by Queen Elizabeth II on 6 November 1981, nine days before regular Metro service began. It was one of two major bridges built specifically for the Tyne and Wear Metro, the other being the Byker Viaduct crossing the Ouseburn valley. In 2006, Nexus, operators of the Metro, commissioned artist Nayan Kulkarni to install a huge artwork on the bridge. The artwork, "Nocturne", sees the bridge painted two distinct tones of blue, while at night, 140 "Lumiflood