The English Channel (French: la Manche, Breton: Mor Breizh, Cornish: Mor Bretannek), often referred to simply as the Channel, is an arm of the Atlantic Ocean that separates southern England from northern France, and joins the North Sea to the Atlantic. It is about 560 km (350 mi) long and varies in width from 240 km (150 mi) at its widest to 34 km (21 mi) in the Strait of Dover. It is the smallest of the shallow seas around the continental shelf of Europe, covering an area of some 75,000 km2 (29,000 sq mi).
Cuckmere Haven (also known as the Cuckmere Estuary) is an area of flood plains in Sussex, England where the river Cuckmere meets the English Channel between Eastbourne and Seaford. The river is an example of a meandering river, and contains several oxbow lakes. It is a popular tourist destination with an estimated 350,000 visitors per year, where they can engage in long walks, or water activities on the river. The beach at Cuckmere Haven is next to the famous chalk cliffs, the Seven Sisters.
At low tide, one can spot ironwork in the sea close to the river mouth. This is the wreck of the Polynesia, a German sailing ship that ran aground in April 1890 west of Beachy Head; it was laden with a cargo of sodium nitrate.