The Split Mound Cave

Useful Information

Location: At the main road to Thorlakshofn, Hveragerdi. East of the road, where the road starts descending in the South.
Open: No restrictions.
Fee: free.
Classification: ExplainLava tube, ExplainIce cave.
Light: bring torch none
Dimension: L=1,360m
Guided tours:  
Address: Extreme Iceland, Gylfaflöt 20, 112 Reykjavik, Iceland, Tel: +354-565-9320, Mobile: +354-898-5448. E-mail: contact
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
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This lava tube is about 1,360m long, 10-30m wide and up to 10m high. The average thickness of the ceiling is about 12 meters. On one point the road crosses the cave and the ceiling is much thinner. The traffic continually destroys the lava and so the ceiling becomes thinner and thinner. Probably it will become necessary to sustain the road in the future.

The cave is a ice cave of the cold trap type. All openings are going up to the surface, so cold air flowing downwards into the cave is trapped. The cave is famous for its ice formations, but also for many lava formations. The ice exists only during winter, and while the formations are interesting and beautiful, the ice coating on the rocks makes visits during winter more dangerous.

The tube has four entrances, and it is possible to visit the cave sections by entering through one and leaving through the next. At the upper section the cave forks into three passages, which means there were originally three lava flows which joined and formed a single flow.

The Leitahraun lava field in which the cave is situated, was formed during a fissure eruption about 5,000 years ago. It belongs to an 11km long crater row.