Mardalsfossen is the Norwegian waterfall with a total drop of about 705 metres in Møre og Romsdal.
The waterfall is created by the Mardøla river in the municipality of Molde, within the Eikesdalen valley. It descends in two principal stages, with the upper fall accounting for much of its overall height. The highest uninterrupted section is commonly given as about 297 metres, while the full vertical descent is approximately 705 metres.
Mardalsfossen became internationally known during a major environmental protest in 1970. Activists opposed plans to divert the river for hydroelectric power, and the campaign helped make the waterfall a symbol of Norwegian environmental politics. The river is still regulated, so the waterfall’s visible flow is strongest during the summer tourist season, when water is released.
The falls are sometimes confused with Vøringsfossen or Vettisfossen, other famous Norwegian waterfalls with different heights and locations.