The Thames is a major river flowing through southern England. While best known because its lower reaches flow through central London, the river flows through several other towns and cities, including Oxford, Reading and Windsor.
The river gives its name to the Thames Valley, a region of England centred around the river between Oxford and West London, and the Thames Gateway, the area centred around the tidal Thames and the Thames Estuary to the east of London.
The River Thames is the longest river entirely in England, rising officially at Thames Head in Gloucestershire, and flowing into the North Sea at the Thames Estuary. It has a special significance in flowing through London, the capital of the United Kingdom, although London only touches a short part of its course. The river is tidal in London with a rise and fall of 7 metres (23 ft) and becomes non-tidal at Teddington Lock. The catchment area covers a large part of South Eastern and Western England and the river is fed by over 20 tributaries. The river contains over 80 islands, and having both seawater and freshwater stretches supports a variety of wildlife.
The river has supported human activity from its source to its mouth for thousands of years providing habitation, water power, food and drink. It has also acted as a major highway both for international trade through the Port of London, and internally along its length and connecting to the British canal system. The river’s strategic position has seen it at the centre of many events and fashions in British history, earning it a description as “Liquid History”. It has been a physical and political boundary over the centuries and generated a range of river crossings. In more recent time the river has become a major leisure area supporting tourism and pleasure outings as well as the sports of rowing, sailing, skiffing, kayaking, and punting. The river has had a special appeal to writers, artists, musicians and film-makers and is well represented in the arts. It is still the subject of various debates about its course, nomenclature and history.
The Thames has a length of 215 miles (346 km). Its usually quoted source is at Thames Head (at grid reference ST980994), about a mile north of the village of Kemble and near the town of Cirencester, in the Cotswolds. However, Seven Springs near Cheltenham, where the river Churn rises, is also sometimes quoted as the Thames' source, as this location is furthest from the mouth both in distance along its course and as the crow flies. The springs at Seven Springs also flow throughout the year, while those at Thames Head are only seasonal.
The Thames flows through or alongside Ashton Keynes, Cricklade, Lechlade, Oxford, Abingdon, Wallingford, Goring-on-Thames, Reading, Henley-on-Thames, Marlow, Maidenhead, Windsor, Eton, Staines and Weybridge, before entering the Greater London area. The present course is the result of several minor redirections of the main channel around Oxford, Abingdon and Maidenhead and more recently the creation of specific cuts to ease navigation.
From the outskirts of Greater London, the river passes Hampton Court, Kingston, Teddington, Twickenham, Richmond (with a famous view of the Thames from Richmond Hill), Syon House and Kew before flowing through central London. In central London, the river forms one of the principal axes of the city, from the Palace of Westminster to the Tower of London and was the southern boundary of the mediaeval city, with Southwark on the opposite bank.
Once past central London, the river passes between Greenwich and the Isle of Dogs, before flowing through the Thames Barrier, which protects central London from flooding in the event of storm surges. Below the barrier, the river passes Dartford, Tilbury and Gravesend before entering the Thames Estuary near Southend-on-Sea.