Hydnefossen is one of the prominent icefalls in Hemsedal. South of Ulsåk points a road sign to the Avfall Mottak. But instead of turning left turn right and park the car below the fall on the left hand side of the road. It took us about 1.5 hours to cover the 460 m elevation and 1.5 km distance. There was a track leftovers, which we could follow. Most of the path was in the stream Hydna.