Reykjadalur Hot Spring Thermal River

Reykjadalur means "Steam Valley", and the hills above Hveragerði live up to it — fumaroles, mud pools and hot springs steam all around. A marked path climbs the valley to a stream where scalding geothermal water mixes with cold snowmelt and cools to bathing temperature along one stretch, where boardwalks and changing dividers mark the spot. It is about 3 km each way with a steep first climb, so it is a soak you earn, not one you drive to.