Kalmanstunga, the easternmost and furthest inland farm in the Borgarfjörður district, over 40 km from the sea. It has always been a substantial farm, its land extending over the whole of the Arnarvatnsheiði moor and the Hallmundarhraun lava field. Many trees. It was once on the main horseback route to the north via Kaldidalur, Stórisandur and Arnarvatnsheiði.