Strait of Dover
From Openwaterpedia

White Cliffs of Dover
The Strait of Dover or Dover Strait is the strait at the narrowest part of the English Channel. The shortest distance across the strait is from the South Foreland, 6 km northeast of Dover in the county of Kent, England, to Cap Gris Nez, a cape near to Calais in the French département of Pas-de-Calais, France.
Open Water Swimming
The most popular and renowned channel swim in the world is across the Strait of Dover.