A narrow-gauge railway is a railway with a track gauge narrower than 1,435 mm standard gauge. Most narrow-gauge railways are between 600 mm and 1,067 mm.
Comparison of standard gauge and three foot narrow gauge wheelsets
1556 woodcut from De re metallica, showing a narrow-gauge railway in a mine
An Electric Tilt Train in Queensland. Unlike other states in Australia which use different gauges, Queensland's network is made up of 3 ft 6 in (1,067 mm)-gauge track.
The 3 ft (914 mm) gauge Disneyland Railroad in California
Railways with a track gauge of 3 feet 6 inches were first constructed as horse-drawn wagonways. The first intercity passenger railway to use the 3 ft 6 in gauge was constructed in Norway by Carl Abrah
JA1271 with excursion consist climbing the Opapa incline in New Zealand
Cape gauge X'Trapolis Mega and Class 5M2 in Cape Town, South Africa
Tram descending the Great Orme Tramway
Dual gauge track in Perth Australia with both 3ft 6in and standard gauge