Situated between Landmannalaugar and Kirkjubæjarklaustur, Eldgjá is the largest volcanic canyon in the world, 270m deep and 600m wide at its greatest. . It was discovered by Þorvaldur Thoroddsen in 1893.
The first documented eruption in 934 was the largest flood basalt in historic time. An estimated 18 km³ of lava poured out of the earth. 
There is a waterfall named Ófærufoss within the canyon. A natural bridge across the waterfall vanished in 1993 due to excess water from melting ice.