<Table> <Tr> <Td_colspan="2"> River Thames </Td> </Tr> <Tr> <Td_colspan="2"> River </Td> </Tr> <Tr> <Td_colspan="2"> Central London with Tower Bridge </Td> </Tr> <Tr> <Th> Country </Th> <Td> England </Td> </Tr> <Tr> <Th> Counties </Th> <Td> Gloucestershire, Wiltshire, Oxfordshire, Berkshire, Buckinghamshire, Surrey, London, Kent, Essex </Td> </Tr> <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Th> Towns / cities </Th> <Td> Cricklade, Lechlade, Oxford, Abingdon, Wallingford, Reading, Henley - on - Thames, Marlow, Maidenhead, Windsor, Staines - upon - Thames, Walton - on - Thames, Kingston upon Thames, Teddington, Westminster, London </Td> </Tr> <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Th> Source </Th> <Td> </Td> </Tr> <Tr> <Td> - location </Td> <Td> Thames Head, Gloucestershire, UK </Td> </Tr> <Tr> <Td> - elevation </Td> <Td> 110 m (361 ft) </Td> </Tr> <Tr> <Td> - coordinates </Td> <Td> 51 ° 41 ′ 39" N 2 ° 01 ′ 47" W ﻿ / ﻿ 51.69426 ° N 2.02972 ° W ﻿ / 51.69426; - 2.02972 </Td> </Tr> <Tr> <Th> Mouth </Th> <Td> Thames Estuary, North Sea </Td> </Tr> <Tr> <Td> - location </Td> <Td> Southend - on - Sea, Essex, UK </Td> </Tr> <Tr> <Td> - elevation </Td> <Td> 0 m (0 ft) </Td> </Tr> <Tr> <Td> - coordinates </Td> <Td> 51 ° 29 ′ 56" N 0 ° 36 ′ 31" E ﻿ / ﻿ 51.4989 ° N 0.6087 ° E ﻿ / 51.4989; 0.6087 Coordinates: 51 ° 29 ′ 56" N 0 ° 36 ′ 31" E ﻿ / ﻿ 51.4989 ° N 0.6087 ° E ﻿ / 51.4989; 0.6087 </Td> </Tr> <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Th> Length </Th> <Td> 346 km (215 mi) </Td> </Tr> <Tr> <Th> Basin </Th> <Td> 12,935 km (4,994 sq mi) </Td> </Tr> <Tr> <Th> Discharge </Th> <Td> for London </Td> </Tr> <Tr> <Td> - average </Td> <Td> 65.8 m / s (2,324 cu ft / s) </Td> </Tr> <Tr> <Td> - max </Td> <Td> 370 m / s (13,066 cu ft / s) </Td> </Tr> <Tr> <Td_colspan="2"> Discharge elsewhere (average) </Td> </Tr> <Tr> <Td> - entering Oxford </Td> <Td> 17.6 m / s (622 cu ft / s) </Td> </Tr> <Tr> <Td> - leaving Oxford </Td> <Td> 24.8 m / s (876 cu ft / s) </Td> </Tr> <Tr> <Td> - Reading </Td> <Td> 39.7 m / s (1,402 cu ft / s) </Td> </Tr> <Tr> <Td> - Windsor </Td> <Td> 59.3 m / s (2,094 cu ft / s) </Td> </Tr> <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Td_colspan="2"> Map of the Thames within southern England </Td> </Tr> </Table> <Tr> <Td_colspan="2"> River Thames </Td> </Tr>

What is the source of the thames river
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