Tottenham Marshes

The Tottenham Marshes are located at Tottenham in the London Borough of Haringey. The marshes cover over 100 acres (0.40 km2) and became part of the Lee Valley Park in 1972. The marsh is made up of three main areas; Clendish Marsh, Wild Marsh West and Wild Marsh East. The latter two are separated by the River Lea.

The Wikipedia page is.