The Ouse Washes are the area between two tributaries of the River Great Ouse: the Old Bedford River and the New Bedford River (also known as the Hundred Foot Drain).
The habitat is mainly grassland which floods in winter. It is then of importance for ducks, waders and swans. It is of national importance for Bewick's Swan and Whooper Swan.
It also attracts wintering birds of prey, including Hen Harrier, Merlin, Peregrine and Short-eared Owl.