The Simplon Tunnel is a railway tunnel that connects Brig, Switzerland and Domodossola, Italy, through the Alps, but not under Simplon Pass itself. It is straight except for short curves at either end. It actually consists of two single-track tunnels built nearly 20 years apart. The first to be opened is 19,803 m (64,970 ft) long; the second is 19,824 m (65,039 ft) long, making it the longest railway tunnel in the world until the opening of the Daishimizu Tunnel in 1982.