An arm of the Atlantic Ocean between western France and southern England. It opens into the North Sea and is traversed by a train-ferry service. A rail tunnel beneath the English Channel, known as the "chunnel," connecting Folkstone, England and Calais, France, was opened in 1994. the English Channel the Channel the narrow piece of water between southern England and northern France, which French people call 'La Manche'. or the Channel French La Manche ("The Sleeve") Strait between southern England and northern France. It connects the Atlantic Ocean with the North Sea through the Strait of Dover. The French name, La Manche ("The Sleeve"), is a reference to its shape, which gradually narrows from about 112 mi (180 km) in the west to only 21 mi (34 km) in the east, between Dover, Eng., and Calais, France. Historically both a route for and a barrier to invaders of Britain, it developed into one of the world's busiest sea routes for oil tankers and ore carriers. The Channel Tunnel, completed in 1994, provides a land route between Paris and London