The Channel Tunnel is a 31-mile long railway tunnel connecting England and France beneath the English Channel. It is the longest undersea tunnel in the world and is considered a marvel of modern engineering. The tunnel has been in operation since 1994 and has allowed for faster and more efficient travel between the
From Wikipedia
The Channel Tunnel, sometimes referred to as the Chunnel, is a 50.46-kilometre (31.35-mile) railway tunnel beneath the English Channel which connects Folkestone in the United Kingdom with Coquelles in northern France. Opened in 1994, it remains the only fixed link between Great Britain and the European mainland.