Lötschberg Railway (löch´bĕrkh), electrical railroad, crossing the Bernese Alps from Thun, W central Switzerland, to Brig, on the Rhône River, S Switzerland. It passes through the Lötschberg Tunnel (9 mi/14 km long; alt. 4,078 ft/1,243 m) under Lötschen Pass and emerges in the Lötschen Valley. Built in 1911, it is one of the world's longer railway tunnels.
The significantly longer Lötschberg Base Tunnel (21.5 mi/34.6 km long), is the longest railway tunnel on land. Built 1999–2007, it runs from Raron (alt. 2,146 ft/654 m) in the Rhône valley (Valais Canton) under the Lötschen Valley to Frutigen (alt. 2,548 ft/777 m) in the Kander valley (Bern Canton). In conjunction with the Simplon Tunnel to the south, it forms an uninterrupted north-south European high-speed rail line through Switzerland; it is not part of the Lötschberg Railway.