The first element is from the name of the valley Mardalen and the last element is the finite form of foss which means "waterfall". The name of the valley is a compound of an old river name Mara (now Mardøla) and the finite form of dal which means "dale" or "valley". The old name of the river is probably derived from the verb mara which means "rub", "grave", "dig" or "die."
Scheffel, Richard L.; Wernet, Susan J., eds. (1980). Natural Wonders of the World. United States of America: Reader's Digest Association, Inc. p. 230. ISBN 0-89577-087-3. 0-89577-087-3 ↩
"Statistical Yearbook of Norway 2013 Geographical survey". http://www.ssb.no/a/english/aarbok/kart/i.html ↩
"Mardalsfossen". World Waterfall Database. https://www.worldwaterfalldatabase.com/waterfall/Mardalsfossen-14/ ↩
"Mardøla". Store norske leksikon (in Norwegian). Foreningen Store norske leksikon. https://snl.no/Mardøla ↩
"Philosophers don't have to climb mountains..." Archived from the original on 30 June 2012. https://archive.today/20120630114211/http://www.ntnu.no/gemini/2002-06e/28-30.htm ↩
"Mardalsfossen Art Projects Official Website". http://www.mardalsfossen.com ↩