Reykjavatn is approx. 1.8 km² in area and is about 510 meters above sea level. It lies on the outskirts of Hallmundarhraun and is lush with vegetation and has great natural beauty. Clear springs flow to the surface of the lake in many places. The fish in the lake are large and both brown trout and char are caught. Reyká flows from the lake to Norðlingarfljót and is included with permits for the lake. There are good fish in the river as well as the lake. The track to the lake is only accessible by modified jeeps.