Jökulsárgljúfur National Park is a former national park situated in the north of Iceland around the river Jökulsá á Fjöllum. It lies to the north of the Dettifoss waterfall. On 7 June 2008, it became a part of the larger Vatnajökull National Park.
The area is of interest because of its chaotic canyon and volcanic mountains. Eight thousand years ago, a volcano erupted directly underneath the river and glacial ice. This caused explosions and chaotic flooding.
The center of the park was Hljóðaklettar (rock of echoes). Rauðhólar (red mountain) is of interest because of its special colouring. Another sight is the canyon of Ásbyrgi to the north of the park which is formed like a horseshoe.