Lake Herbjarnarfellsvatn is in a beautiful bowl under Herbjarnarfell, a little northwest of the huts by Landmanna-cave. It is at an altitude of 630 m above sea level and its estimated area is 0.54 km². In the lake, it was a good fishing earlier in time, but brown trout were released into it in 1967. There were examples of up to 7-pound fish, but now it is different. Herbjarnarfellsvatn is full of rather small brown trout, but a good fish to eat. The lake has never been netted, but it is much needed. There is a good road to the lake.