The Mardalsfossen waterfall cascades 297 metres down into the valley and is the fourth highest waterfall in the world (the whole waterfall is 655 m).

The waterfall is an impressive sight in the period when the water is released by the hydroelectricity company - from 20th June to 20th August each year.

The walk up to the waterfall takes about 30 minutes. Large car park with kiosk (open i summer) and information boards in Mardalen.