The Channel tunnel is the longest underwater tunnel in the world. It goes under the English Channel,connecting the Unider Kingdom and France.The tunnel was started in 1988,and it was finished in 1943.the two rail tunnels in the Channel Tunnel have a height of 7.6meters,a width of 7.6meters,and a lenght of 50.5 kilometers. About 20000 people travel through the Channel Tunnel every day.