It lies between Wells-next-the-Sea, Holkham and Burnham Overy, and the total area is 3850 hectares. It includes a wide range of habitats: sandflats, sanddunes, saltmarsh, grazing marsh, mixed woodland.
Many rare species of wildlife can be found here. Amongst the flora there is the "Red Book Data" species Jersey cudweed; amongst the birds, Brent goose, pink-footed goose, wigeon, bittern, marsh harrier, avocet, bearded tit and garganey.