A mountain railway is a railway that operates in a mountainous region. It may operate through the mountains by following mountain valleys and tunneling beneath mountain passes, or it may climb a mountain to provide transport to and from the summit.

A funicular is a type of cable railway system that connects points along a railway track laid on a steep slope. The system is characterized by two counterbalanced carriages permanently attached to opposite ends of a haulage cable, which is looped over a pulley at the upper end of the track. The result of such a configuration is that the two carriages move synchronously: as one ascends, the other descends at an equal speed. This feature distinguishes funiculars from inclined elevators, which have a single car that is hauled uphill.