Opening of the first rack railway in Europe, the Rigi Bahnen on Mount Rigi.

A rack railway is a steep grade railway with a toothed rack rail, usually between the running rails. The trains are fitted with one or more cog wheels or pinions that mesh with this rack rail. This allows the trains to operate on steep gradients of 100% or more, well above the 10% maximum for friction-based rail. The rack and pinion mechanism also provides more controlled braking and reduces the effects of snow or ice on the rails. Most rack railways are mountain railways, although a few are transit railways or tramways built to overcome a steep gradient in an urban environment. The first cog railway was the Middleton Railway between Middleton and Leeds in West Yorkshire, England, United Kingdom, where the first commercially successful steam locomotive, Salamanca, ran in 1812. This used a rack and pinion system designed and patented in 1811 by John Blenkinsop.

Rigi Railways is a railway company that operates a group of railways on the mountain Rigi, located between two of the arms of Lake Lucerne, in Switzerland. They include two standard gauge rack railways, the Vitznau–Rigi Bahn (VRB) and the Arth–Rigi Bahn (ARB), along with the Luftseilbahn Weggis–Rigi Kaltbad (LWRK) cable car.

The Rigi is a mountain massif of the Alps, located in Central Switzerland. The whole massif is almost entirely surrounded by the water of three different bodies of water: Lake Lucerne, Lake Zug and Lake Lauerz. The range is in the Schwyzer Alps, and is split between the cantons of Schwyz and Lucerne, although the main summit, named Rigi Kulm, at 1,797 meters above sea level, lies within the canton of Schwyz. The Rigi Kulm Hotel, established in 1816, is located on the summit.