Hungry for adventure journey into the depths of a dormant volcano on this exhilarating 5 hour expedition from reykjavik after a hike through the lava fields of the blue mountains arrive at the rim of the thrihnukagigur volcano don a helmet and harness and descend by open elevator into the vast subterranean chamber ogle the rock walls and dome and learn how thrihnukagigur last erupted 4 000 years ago filling the crater with burning lava before ascending back up numbers are limited to 15