Beginning of River Thames

The River Thames, known alternatively in parts as the River Isis, is a river that flows through southern England including London. At 215 miles, it is the longest river entirely in England and the second-longest in the United Kingdom, after the River Severn.
  • Etymology: Proto-Celtic *tamēssa, possibly meaning "dark"
  • Country: England
  • Counties: Gloucestershire, Wiltshire, Oxfordshire, Berkshire, Buckinghamshire, Surrey, Greater London, Kent, Essex
  • Towns/cities: Cricklade, Lechlade, Oxford, Abingdon, Wallingford, Reading, Henley-on-Thames, Marlow, Maidenhead, Windsor, Staines-upon-Thames, Walton-on-Thames, Sunbury-on-Thames, Kingston upon Thames, London (inc. Twickenham, the City), Dagenham, Erith, Dartford, Grays, Gravesend
  • Mouth: Thames Estuary, North Sea
  • Length: 215 mi (346 km)
  • Basin size: 12,935 km² (4,994 sq mi)
Data from: en.wikipedia.org