The Dettifoss waterfall is with the greatest volume of any waterfall in Europe, 500 cubic metres of water per second plunges over the edge. Dettifoss is 45 m high and 100m wide. A nice hiking trail, 34km, goes along the canyon from Dettifoss to Asbyrgi. Camping possible in Vesturdalur.
Road 864 goes from road 85 past Dettifoss on the east side towards road 1. This is a gravel road and driving speed depends on road conditions each time. Road 864 is closed durning winter time due to snow or wet condtitions (muddy road) and does not open until early summer (end of May).
Gravel road 862 is on the west side of river Jökulsá. The road is passable for normal vehicles from Asbyrgi to Dettifoss, with Vesturdalur (Hljodaklettar) and Holmatungur between. Up until 2011 this road was categorised as a mountain road (F-road) but is now served as a gravel road. The conditions of gravel roads in Iceland can vary, so travellers are asked to be aware of road conditions at any time and adjust driving speed to the conditions.
Road 862 is closed durning winter time, due to snow or wet conditions (muddy road) and does not open until late May or early June. From Dettifoss onwards south to road 1, on the west river bank, there is a new, paved road which is passable for all vehicles. This road is not in service from January until the beginning of April.