Lake Hraunsvatn is located at the mouth of Vatnsdalur, which lies between Þverbrekkuhnjúkur and Drangafjall in Öxnadalur. It is at 492 m above sea level and is 0.8 km² in area. It is in the land of Hraun and Háls in Öxnadalur. Hraunsá flows from the lake for about 200 – 300 m before it disappears into the lava above the town Hraun. There is an enormous number of small char in the lake, barely larger than 1 pound. There are also predatory char, so there are two distinct char populations. The predator char can be big and fish up to 10 pounds have been caught. The downside, however, is that there seems to be very few of them and they take only spinners that are thrown far into the deep lake. The best time to fish the lake is the first part of July, because it takes longer for ice to dissolve and the biota to recover than in other lakes. From the town of Háls it is a 30-minute walk to the lake and this is a popular hiking trail, both for anglers and other outdoor enthusiasts.