The Simplon Pass is a high mountain pass between the Pennine Alps and the Lepontine Alps in Switzerland. It connects Brig in the canton of Valais with Domodossola in Piedmont. The pass itself and the villages on each side of it, such as Gondo, are in Switzerland. The Simplon Tunnel was built beneath the vicinity of the pass in the early 20th century to carry rail traffic between the two countries.