Eldgjá Canyon in the south of Iceland is the world’s largest volcanic canyon, measuring 270 m (885.8 ft) in depth and 600 m (1,968.5 ft) wide at its largest point. Situated between the mountains of Kirkjubæjarklaustur and Landmannalaugar, this huge fissure was caused in 934 AD by volcanic eruptions. The lava from its flow is thought to cover 700 km2 (270.2 sq mi).
From the car park there is a short walk into the canyon itself, where the power of volcanic activity makes itself felt. Unlike a valley created by water erosion, Eldgjá runs in a near-perfect straight line and the bottom is flat. There are small caves/cavities caused by bubbles of gas escaping from the rocks. The Ófærufoss waterfall also lies within the canyon.
The canyon contains an active geocache site, for those who practice this activity.