Surtshellir

About Surtshellir

Surtshellir is a lava tube in the Hallmundarhraun lava field in West Iceland, around 60 km from Borgarnes and inland from the Húsafell area. It is almost 2 km long, and together with the neighbouring Stefánshellir it forms a cave system of about 3.5 km, the longest lava cave in Iceland. The lava field itself came from a large eruption near Langjökull around AD 900 that buried some 240 square kilometres of land.

The cave is named after Surtr, the fire giant of Norse mythology. It has been known for centuries: Eggert Ólafsson documented it in detail on his travels in 1750, and it is often described as one of the first lava tubes studied by modern cave scientists. Excavations in 2001, 2012 and 2013 found evidence of Viking Age ritual activity inside the cave in the decades before Iceland converted to Christianity around AD 1000.

Inside, the main tunnel reaches around 10 metres high and 15 metres wide, with walls of glazed lava and layered basalt. The westernmost section, called Íshellir (the Ice Cave), has a lower ceiling and permanent ice, with ice formations on the floor and walls.

Unlike the nearby Víðgelmir, which is visited on guided tours, Surtshellir is unmanaged and free to enter, with no lighting or walkways. The floor is a jumble of rough, loose rock and ice, so bring a helmet, strong boots, warm clothing and more than one light, and do not go in alone. Access is via the F578 mountain road towards Arnarvatnsheiði, which is closed in winter, so it is only realistic to visit in summer.