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 National Trust Queen Elizabeth II National Trust The Queen Elizabeth II National Trust (National Trust) is a registered charity and statutory New Zealand organisation independent from Government and managed by a Board of Directors. It was established in 1977 by the Queen Elizabeth the Second National Trust Act 1977 "to encourage and promote, for the benefit of New Zealand, the provision, protection, preservation and enhancement of open space." The organisation enables landowners to protect special features on their land through its open space covenants. The National Trust also owns 27 properties, including Aroha Island, which collectively protect 1,582 hectares of significant habitat.