Niesenbahn, Mountain funicular in Aeschi bei Spiez and Reichenbach im Kandertal, Switzerland.

The Niesenbahn is a two-section funicular from Mülenen (693 m) to the Niesen summit station at 2,336 m. Its 3,499 m line, with a maximum gradient of 68%, passes the intermediate station of Schwandegg at 1,669 m.

A first project envisaged a rack railway from Wimmis, but in 1902 builder Johann Frutiger of Oberhofen obtained the concession for a funicular from Mülenen. Work began on 26 August 1906 with up to 350 men employed in 1909; the first section to Schwandegg opened in 1908, the whole line on 15 July 1910, carrying 150 guests up in 50 minutes. The cost reached 1,755,000 francs.

The line's name comes from the Niesen, the pyramid-shaped mountain above Lake Thun that it climbs. Since 2004 the annual Niesenlauf foot race sends runners up the 11,674-step service stairway alongside the track, with 1,643 metres of ascent; Jonathan Schmid holds the course record. The Swiss Post marked the railway's centenary in 2010 with an 85-centime stamp showing the line against the Bernese Oberland panorama.

The line runs in two sections with a change at Schwandegg, the middle station at 1,669 m. Cars leave every 30 minutes between 08:00 and 17:00, with 15-minute intervals at busy times and some evening services. The railway operates from late April to mid November, so check the season before travelling up.

The service stairway beside the track has 11,674 steps and climbs 1,669 m, which the Guinness Book of Records lists as the longest stairway in the world. It is normally reserved for employees, but the Niesenlauf race has been held on it every year since 2004.