Surtshellir is Iceland´s most well-known lavacave, once inhabited by outlaws and sheep rustlers.
It is an enormous lava tube which is easily explored if the right gear is used.
The cave is 1310 m long and 8-10 m high, but at the west end it is only 2-4 m high. Walking in the cave is made more difficult by large rocks that have fallen from the roof. The interior of the cave contains "lavacicles" and ice formations.