Frays Farm Meadows is a 28.2-hectare (70-acre) biological Site of Special Scientific Interest near Denham in the London Borough of Hillingdon.

[4] Frays Farm Meadows are a set of fields bounded on the south by the A40 road and on the west by the Grand Union Canal.

From there a path through Denham Lock Wood (another SSSI run by London Wildlife Trust, north-west of the Meadows) gives access to the northern and eastern fields.

[1] Cows and horses graze in order to improve conditions by churning up the ground and encouraging pooling of water.

Mammals on site include the nationally endangered water vole, and there are birds such as snipe, cuckoos, and a barn owl.