Eldgjá canyon
Eldgjá is an old tectonic graben reactivated in a massive eruption in 934-940. The Eldgjá vents form a discontinuous 75 km long volcanic fissure extending from the Katla volcano in the west to Vatnajökull in the east. The eruption in 934-940 takes its name from a spectacular 150 m deep and 8 km long chasm called Eldgjá (fire fissure) that occupies the central part of the vent system. Part of the fissure is under the protection of the Vatnajökull National Park. There you can take a walk along the bottom of the fissure and witness the sheer scale of it. An easy hike takes you from the car park (with WC facilities) along the bottom of the fissure to Ófærufoss waterfall. Getting there: you need a 4x4, and the area is only accessible in the summer. Eldgjá is a site of international geological significance. Ófærufoss is a distinctive two-tiered waterfall cascading into the fissure Eldgjá.
Eldgjá is reached by the mountain road Fjallabaksleið nyrðri (F 208), west of Kirkjubæjarklaustur. All roads in the western part of the national park are mountain tracks, only navigable for vehicles with four-wheel-drive; some only for large jeeps. Some sections of the road are rocky and full of potholes, and loose gravel is common. It is sometimes necessary to ford (drive-through) streams and rivers, which can suddenly become swollen, making them difficult or even impossible to cross. It is dependent on the weather when the roads are opened. Usually, they are open from early June through to autumn. Driving is only allowed on the roads marked on the accompanying map. All other roads or tracks are closed to the public. Here, as elsewhere in Iceland, driving off-road is banned by law.