The body of water that separates the UK from continental Europe is the English Channel. This narrow stretch of water, approximately 21 miles at its narrowest point, connects the North Sea to the Atlantic Ocean. It is historically significant, serving as a natural barrier and a route for trade and military movements. The Channel is also popular for recreational activities like sailing and swimming, evidenced by events like the annual English Channel swim. Its importance in geopolitics, history, and culture highlights its role in shaping the relationship between the UK and neighboring European countries.