Hallmundarhraun flowed from an eruption a volcano lying under Langjokull glacier around the year 930. Consisting of dark basaltic rocks covered in soft moss, Hallmundarhraun has wonderful formations, frozen ripples, crevasses. 

Furthermore, Hallmunderhraun contains many caves under the lava. The most famous caves are Vidgelmir, Stefanshellir and Surtshellir.  In particular, Vidgelmir cave is an interesting visit. It is one of the longest lava caves in the country. Its has beautiful colors and formations.  Archeologists have found signs that people lived here during Viking times.  A local family has set up infrastructure and lighting, so anyone in reasonable shape can easily enjoy this beautiful place on a tour led by certified cave guides.

The ancient lava Hallmundarhraun gets it name from a cave-dwelling giant mentioned in the Saga of Grettir the Strong. According to Grettir’s Saga,  Hallumdur the Giant lived in this area.

How did Hallmundarhraun form?

Hallmundarhraun formed shortly after Iceland’s settlement, in the 10th century (most likely around 940 AD). The lava flowed from craters beneath the Langjokull, Iceland’s second largest glacier. The eruption lasted for several years. It is over 200 km² (77 miles²) in area. The largest section of the lava is 7 km (4,3 miles), and its total length is 52 km (32 miles).


A remarkable narrative of Hallmundarhraun’s volcanic eruption comes from an ancient song called Hallmundarkvida (Poem of Hallmundur). Importantly, this is the oldest description of an eruption in Iceland. The poem mentions earthquakes, ash, lava flow and deaths caused by the eruption. Moreover, there may be remains of farmsteads that went under the lava.

Where is Hallmundarhraun?

This lava field is a part of the Borgarfjordur region. Actually, it lies on the boundary between the Highlands and West Iceland. One of the best ways to experience the region is on a guided tour of one of the caves in the area.  You can combine a visit to the area with visits to Hraunfoss waterfall, Deildartunguhver hot springs and the Krauma Spa.  Or you could have an ice and lava experience and combine a visit to Vidgelmir cave in Hallmundarhraun with the Into the Glacier experience ice cave experience on Langjokull!