Wikipedia
Korketrekkeren (direct translation: "The Corkscrew") is a tobogganing track and former bobsleigh and luge track in Oslo, Norway. The tobogganing track runs between Frognerseteren and Midtstuen and is operated as a public venue by the municipality. Return transport to the top of the hill is undertaken by riding the Oslo Metro's Holmenkollen Line. Tobogganing in the area started in the 1880s, with several roads being used during winter evenings. Auto racing took place in the hill in 1921 and the following year it saw its first luge tournament. The first major tournament was the FIL European Luge Championships 1937. Tobagganing also took place in the nearby Heftyebakken, but from 1950 Korketrekkeren became the sole tobogganing hill and Heftyebakken was used for cross-country skiing.
The bobsleigh track was built for the 1952 Winter Olympics, where it hosted two bobsleigh events. Contrary to popular belief, this was not built at Korketrekkeren but as a separate run nearby also starting at Frognerseteren. It was built as a temporary, artificial track with the curves being constructed in snow and then frozen hard to ice. Trial runs were undertaken in 1951 and the bobsleigh course was not used after 1952. Both Olympic events were won by Germany, with Andreas Ostler and Lorenz Nieberl participating in both winning teams. The tobogganing hill hosted the inaugural FIL World Luge Championships 1955, with Norway's Anton Salvesen winning the men's single—the only time in history Norway has won a World Luge Championships medal.