Bifröst is surrounded by a 3,000-year-old Aalava field, Grábrókarhraun, which has been overgrown with moss and heather. It is part of the around 90 km long volcanic system of Ljósufjöll. Just behind the university campus are some craters which produced the lava field, the biggest one is called Grábrók (Stóra Grábrók) and the one beside it Grábrókarfell.