London from the Thames

The River Thames is a river that flows through southern England, most notably through London. At 215 miles, it is the longest river entirely in England and the second longest in the United Kingdom, after the River Severn. It also flows through Oxford, Reading, Henley-on-Thames and Windsor. The lower reaches of the river are called the Tideway, derived from its long tidal reach up to Teddington Lock. It rises at Thames Head in Gloucestershire, and flows into the North Sea via the Thames Estuary. The Thames drains the whole of Greater London.