Narrow-gauge railway
A narrow-gauge railway (narrow-gauge railroad in the US) is a railway with a track gauge (distance between the rails) narrower than 1,435 mm (4 ft 8+1⁄2 in) standard gauge. Most narrow-gauge railways are between 600 mm (1 ft 11+5⁄8 in) and 1,067 mm (3 ft 6 in).