Lower Horse of islands (five of which later re-clustered to form Canvey Island), that broke away from the English coastline in the medieval period. Lower Horse Lower Horse is a uninhabited island off the English coast, lying in the Thames Estuary between Canvey Island and Stanford-le-Hope, close to . Administratively it is part of Thurrock unitary authority; the border with its ceremonial county namely the administrative county of Essex runs between it and Canvey Island. Smaller than normal markings for an area of saltings (traditional, open air, sea salt extraction through drying) appear in the Ordnance Survey map of 1919, which confirms
Dee Estuary channel which it cut through the base of the Wirral Peninsula. The estuary is a major wildlife area and one of the most important estuaries in Britain, amongst the most important in Europe for its populations of waders and wildfowl. The Environment Agency is the Conservation Authority, and the estuary is protected or listed under several schemes: Large parts of the area are within the RSPB's Dee Estuary Nature Reserve. The estuary supports some important natural fisheries, including salmon and trout on their way to and from the freshwater river, as well as sea-fisheries and shell-fisheries, especially cockles. From earliest