Interpretation
Árnahellir is approximately 150 metres long and lies about 20 metres below the surface. The cave is around 10 metres wide, with a low ceiling. Its countless lava stalactites are so densely packed that they have been compared to a forest.
The longest stalactites in the cave are just over one metre long and around 7 cm in diameter. Some are partly coated in gypsum, with layers up to 15 mm thick. The longest lava straws reach about 60 cm, and almost the entire ceiling of the cave is covered with lava straws measuring 5 to 10 mm in diameter.
Unusual minerals have also been found in Árnahellir, including a 2 cm long blue green opal.
Protection Status
Árnahellir was discovered in 1985 and contains geological formations considered to be of international significance. The cave was therefore designated a natural monument in 2002. The purpose of the designation is to protect the cave and its unique geological formations.
The protected area covers 8 hectares. Access to the cave is only permitted with special permission from the Nature Conservation Agency of Iceland.