Mount Akrafjall is a lone and eye-catching mountain that rises between the coastlines of Hvalfjörður Fjord and Leirárvogur Bay. The mountain covers most of its hosting peninsula’s landmass, as it rises close to the coastlines on each side. Its highest summit is Geirmundartindur with a peak of 643 metres.
The distinctive shape of Akrafjall is due to periods of formation during the last Ice Age, where what is now the top of the mountain used to host a glacier. As the glacier melted, it left a noticeable dent in the middle of the mountain, while its slopes remained steep.
Geologists have discovered a history of strandflat in the mountain's sedimentary rock layers, suggesting that it was an island surrounded by water before the glacial retreat. The lava that formed Akrafjall dates back to 4,5-3 million years, with its main rock type being basalt.