We visit the lava tunnel Raufarhólshellir located only 30 minutes from Reykjavík. We will witness the inner workings of a volcanic eruption while we walk in the path of a lava that flowed thousands of years ago. The lava tunnel is one of the biggest in Iceland and gets up to 30 metres wide and 10 metres high. The lava tube ceiling has caved in near the entrance, which creates beautiful columns of light. The fantastic range of colours of the tunnel wall is caused by the different mineral types of the rock.