Purfleet Walk

Rainham Marshes is an RSPB nature reserve in the east of London, adjacent to the Thames Estuary in Purfleet, Thurrock and the London Borough of Havering. In 2000, the area of land was bought from the Ministry of Defence, who used it as a test firing range. With no activity for several years, the nature reserve was officially opened to the public in 2006.

The Mardyke (sometimes, but less frequently, Mar Dyke, occasionally Mardike) is a small river, mainly in Thurrock, that flows into the River Thames at Purfleet, close to the Queen Elizabeth II Bridge. In part, it forms the boundary between the Essex hundreds of Barstable and Chafford. The river gives its name to the Mardyke Valley—a project aimed at increasing appreciation and usage of recreational land around the Mardyke.

Coldharbour is an area of the London Borough of Havering by the River Thames and southwest of the Rainham Marshes Nature Reserve. It is the location of Coldharbour Point, where there has been a lighthouse since 1885. This point is adjacent to the town of Erith in Bexley, across the Thames. The nearest accessible settlement on land is the town of Rainham, which is connected by Coldharbour Lane; the village of Wennington is also nearby but not accessible by road (both are separated by the A13 and marshlands).