... connects Switzerland and Italy, under the Alps (in the vicinity of the Simplon Pass, but not actually under it). It was the world's longest transit tunnel, until 1982, when it was surpassed by the Dai–Shimizu Tunnel (13.8 miles, 22.2 km) in Japan. This in turn was surpassed in 1988 by the Seikan Tunnel.
The Simplon Tunnel actually consists of two single–track tunnels, built several years apart. Construction of the first tunnel began in 1898 and was completed in 1906; the second tunnel was started in 1912 and completed in 1921.
© Haydn Thompson 2017