or is a waterfall in the western part of the Vestfjorddalen valley in Tinn Municipality in Telemark county, Norway. The waterfall is located on the river Måna, about west of the town of Rjukan.
Historically, the waterfall was a major tourist attraction, being one of the first waterfalls to be illuminated by floodlights powered by electricity generated from the waterfall itself. In 1905, the waterfall and surrounding river were harnessed by the Vemork hydro-electrical power plant to produce power for the saltpetre production at a nearby Norsk Hydro factory.
Name The waterfall is named Rjukanfossen in Norwegian (). The first element is derived from the present participle of the verb which means "to emit smoke" or "to emit vapor" (referring to the froth produced by the waterfall).
The last element is a later addition to the name which comes from the Norwegian word which means "the waterfall".
See also
List of waterfalls#Norway Rjukandefossen
References