Mt. Botnsulur (1095m) is a cluster of peaks of an extinct central volcano between the Thingvellir area and The Whale Bay in the West. The view from the peaks is fascinating on a fine day, but the climb requires caution, especially in the snowy areas and on the narrow ridges with the steep slopes on both sides.

The ascent takes about three hours. Between the Mt. Botnsulur and Mt. Armannsfell is an old route referred to as the Gagnheidi. Another such route, Leggjarbrjotur, just west of Mt. Botnsulur connects the Thingvellir area and the valley Botnsdalur at the end of the Whale Bay in the West.

Both routes cross at the abandoned farm Svartagil in the Thingvellir County. They have become very popular nowadays because of their beautiful and scenic surroundings.