The Montreux Oberland Bernois Railway ( , , abbreviated MOB), is a railway operating in southwest Switzerland, one of the oldest electric railways in the country; its main line, 62 kilometers in length, built to 1000mm gauge, connects Montreux, Gstaad, and Zweisimmen, where passengers can transfer to the BLS AG owned, and standard gauge, Zweisimmen to Spiez line.