Simplon

Simplon, name applied to an alpine pass (2,009 m/6,591 ft high), road, and the world's deepest tunnel (705 m/2,313 ft high) linking Switzerland and Italy. The road, extending through the pass from Brig, Switzerland, to Domodossola, Italy, was built by the French from 1800 to 1806. It passes across 611 bridges. The construction of Simplon Tunnel, connecting Brig and Iselle, Italy, was begun in 1898 and completed in 1906. A second parallel track was completed in 1922. The Simplon Tunnel, which is 19.8 km (12.3 mi) long, was the longest rail tunnel in the world until the construction of the Channel Tunnel, which is 50 km (31 mi) long, in 1993.