The River Thames is 346 kilometres long. It flows from the source at Kemble, near Cirencester, and ends in the North Sea near Southend-on-Sea, in Essex.
The River Thames is the second longest river in the United Kingdom, behind the River Severn. It rises at Thames Head in Gloucestershire and flows into the North Sea, passing through London, the country’s capital. The Thames also runs through towns and cities, including Reading, Oxford, and Windsor.