Jökulsárgljúfur is a canyon formed by the river Jökulsá á Fjöllum, the source of which is the Vatnajökull ice cap and flows north to Öxarfjörður bay.
North of the Vatnajökull ice cap, the river Jökulsá flows through a gently sloping plateau, dotted with mountains and lava fields. At the edge of the plateau, the land falls away, the current speeds up, and the river plunges in huge waterfalls (Dettifoss, Selfoss, Hafragilsfoss and Réttarfoss) into the canyon that bears its name, Jökulsárgljúfur (the Jökulsá Canyon).
The Jökulsá Canyon is one of the largest canyons in Iceland, some 25 km long, about 1/2 km wide and over 100 m deep in many places.
Iceland 1956, Jökulsárgljúfur.