Lake Hredavatn has an area of 1,14 km², lies 56 m above sea level and its greatest depth is 20 m. Its discharge is Hrauna, which mainly runs under the lava field Grabrokarhraun. The lake is situated a short distance from road nr. 1. The number of permits is not limited. The catch consists mainly of lake char and some brown trout, mostly ½-2 pounders. The surroundings of the lake are extremely beautiful and offer a few possibilities for hiking to charming spots such as the crater Grabrok (view), the waterfalls of the fine salmon river Nordura and the lava spot Paradise near the river. According to the legends some mysterious animal or monster occupied the lake, but is rarely to be seen nowadays.
The distance from the capital is 107 km by the Whale Bay tunnel and 33 km from Borgarnes.