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
M4 Thames Bridge M4 Thames Bridge The M4 Thames Bridge Maidenhead is a motorway bridge between Dorney Reach, Buckinghamshire and Bray near Maidenhead, Berkshire in England built in the 1960s. The bridge carries the M4 Motorway across the River Thames, on the reach above Boveney Lock, and about 500 yards short of Bray Lock. It is one of three bridges carrying motorway traffic across the Thames, the others being the M25 Runnymede Bridge (just below Bell Weir Lock) and the M3 Chertsey Bridge. There is also a pedestrian walkway on either side of the bridge, which allows people to access Bray Village from