Which river flows through London?

The River Thames flows through London. It crosses southern England from Gloucestershire to the Thames Estuary, passing through the capital before entering the North Sea.

At about 215 miles long, the Thames is the longest river entirely in England and the second-longest in the United Kingdom after the River Severn. Within London, it passes landmarks including the Palace of Westminster, the London Eye, Tower Bridge and the Tower of London. Its banks helped London develop as a port, trading centre and political capital.

The river is tidal through much of London. The tidal section, known as the Tideway, extends upstream to Teddington Lock, and the Thames Barrier protects central London from storm surges and flooding. Downstream, the river widens into an estuary before reaching the North Sea.

Some readers confuse the Thames with the Seine, which flows through Paris, or the Rhine, which passes through cities including Cologne and Rotterdam. Another curiosity is that the river is sometimes called the Isis around Oxford. Its name is ancient, probably derived from a Celtic word that may have referred to darkness or the colour of the water.