The most famous cave in Iceland is undoubtedly Surtshellir. Its in the Hallmundarhraun lava field. The total length of the cave is approx. 1970m. The cave Stefanshellir is a direct continuation of Surtshellir to the northeast and together they are by far the longest caves of the country – 3500 m.
The roof of Surtshellir has collapsed in five places, where there are five openings now. The average height of the cave is about 9m, it drops to 2-4m. The innermost part, where the ceiling is lower is called “the ice cave”, where remarkable ice formations, ice candles and columns are seen. This part of the cave is thought to be the most beautiful.
Stone-built walls, signs of human habitation in the past and bones have been found in a part of the cave.