The London Outer Orbital Path — more usually the "London LOOP" — is a 240-kilometre (150 mi) signed walk along public footpaths, and through parks, woods and fields around the edge of Outer London, England, described as "the M25 for walkers". The walk begins at Erith on the south bank of the River Thames and passes clockwise through Crayford, Petts Wood, Coulsdon, Banstead, Ewell, Kingston upon Thames, Uxbridge, Elstree, Cockfosters, Chingford, Chigwell, Grange Hill and Upminster Bridge before ending at Purfleet, almost directly across the Thames from its starting point.