These falls on the Drammen river have long been the site of a paper mill that harnesses the river at this point.
Picture at: http://www.eikerbygda.no/utsiktsbilde10-fra-slettfjell-hellefossen.shtml, and also http://www.eiker.org/Arkiv-OE/Bilder/Presentasjon/Industri/HOK-08-Hellefos.htm.