Mike Knowles started the 1977 campaign to save the Walthamstow Marshes in East London. 88 acres of ancient fenland within four miles of St Paul's in the city, threatened by plans to drain and dig them up for gravel extraction. Rushes, sedges, marsh, grasses, swallows and at least 300 native marsh plants, and bird and animal life such as field mice. The campaign did not just succeed but in 1985 the marshes were declared a site of special scientific interest.