Réttarfoss is the last of the major waterfalls on the glacial river Jökulsá á Fjöllum. Unlike the previous waterfalls, this appears to be only viewable from the west bank and from a distance. The view is very distant so you have to look closely at the river to identify this waterfall. You can walk to a view of the falls along the trail to Dettifoss near the car park for Hólmatungur.