Chertsey is a town in the Runnymede borough of Surrey, England on the right bank of the River Thames where it is met by a corollary, the Abbey River and a tributary, the River Bourne or Chertsey Bourne. It is within a narrow projection of the Greater London Urban Area, aside from the Thames bordered by Thorpe Park, junction 11 of the M25 London orbital motorway, the town of Addlestone and south-western semi-rural villages that were formerly within Chertsey (Lyne, Longcross and Ottershaw). Chertsey is centred southwest of central London, has a branch line railway station and less than north of its developed centre is the M3 (motorway).