It is managed by the Herts and Middlesex Wildlife Trust.
[1] The site is a narrow strip of land between the Frays River and the Shire Ditch, and it was formerly a railway embankment on the Uxbridge High Street branch.
It is wet woodland of crack willow and alder, with areas of marsh.
Plants include birds-foot trefoil and small toadflax, and there are mammals such as the rare Brandt's bat, as well as stoats, weasels and moles.
[1] There is access from Braybourne Close and from a footpath which starts in Harefield Road opposite Gravel Hill, and then crosses the Frays River by a footbridge.