Rainham Marshes protects 411 hectares of ancient, low-lying grazing marsh in the Thames Estuary. Its complex of wet grassland and ditches, together with grassland and scrub, supports many breeding and wintering birds. Wildlife also includes scarce wetland plants and insects, and a key population of the nationally declining water vole.
The RSPB is working to manage important habitats and improve their biodiversity. A former military firing range, the reserve is now developing into a great place to see wildlife, and with lots of the former military heritage still to be seen.