This video descends 300 or so feet inside the magma chamber of a dormant volcano near Reykjavik, Iceland. Fantastic colors on the magma chamber's walls result from minerals that were baked by an eruption that happened some 4,000 years ago. Thrihnukagigur is claimed to be the only place on earth where such an experience is possible, as magma chambers are usually plugged with lava or collapse. This video is part of CGEE's growing collection of educational media about land formation through volcanism in Hawaii and Iceland.