Dettifoss is situated on the
Jökulsá á Fjöllum river, which flows from the
Vatnajökull glacier and collects water from a large area in Northeast Iceland. The falls are 100 metres (330 ft) wide and have a drop of 45 metres (150 ft) down to the Jökulsárgljúfur canyon. It is the largest
waterfall in Iceland in terms of volume discharge, having an average water flow of 193 m3/
s.