Gullfoss is a waterfall located in the canyon of Hv#237;t#225; river in southwest Iceland.br/br/It is a wide curved three-step quot;staircasequot;, first plunging 11 metres and then a further 21 metres into a deep crevice. The crevice, about 20 metres wide, and 2.5#160;km in length, is at right angles to the flow of the river.