Mapping the River Thames: From the Cotswolds Through London to the North Sea

The River Thames flows 346 km (215 miles) across southern England. Its course:

• Source: Trewsbury Mead, Gloucestershire (Cotswold Hills).
• Upper reaches: Through Wiltshire, Oxfordshire, Berkshire, Buckinghamshire.
• London: Passes Windsor, Richmond, Kew, Westminster, the City, Greenwich.
• Estuary: Widens at Thames Estuary, Essex/Kent border.
• Mouth: North Sea.

The Thames is tidal up to Teddington Lock. It has been England's economic artery for centuries, lined with historic landmarks (Parliament, Tower, London Eye).