This is a 17 km. hike from Hveragerði to Sleggjubeinsdalur, home to the geothermal power plant Hellisheiðarvirkjun, through a geothermally active area. There are hot spring creeks that are ideal for bathing in on the trail along with magnificent scenery. The trail crosses 2-3 30-50 cm. deep creeks on the way, so be prepared.