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
Newbridge, River Thames used to build a new bridge upriver, believing that this is the only long-term option available. The idea of a new bridge is opposed by local residents of Standlake who would prefer to see the existing bridge remain open for light traffic only. The bridge has national recognition and statutory protection from alteration. The northern span is listed at maximal Grade I whereas the southern at Grade II*, the second-highest of the three grades of listing, designating "particularly important buildings of more than special interest". Newbridge, River Thames New Bridge is a 13th-century bridge carrying the A415 road over the