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
Queensferry Crossing to August 2017 after several delays. It is the third bridge across the Forth at Queensferry, alongside the Forth Road Bridge completed in 1964, and the Forth Bridge completed in 1890. Following a public vote, it was formally named on 26 June 2013 and opened to traffic on 30 August 2017. The official opening was carried out on 4 September 2017 by Queen Elizabeth II, fifty-three years to the day after she opened the adjacent Forth Road Bridge. A crossing route over the Forth had existed at the site since the eleventh century, when the queen of Scotland, Margaret, founded