This is one of my favourite places in Iceland and is only about 45 minutes drive from Reykjavik! The name Reykjadalur means steam valley and if you visit you will understand why. The actual river that people bathe in is a flowing hot river about 30cm deep. A warning that in order to get to the hot springs it is a reasonably hilly 3.2km hike (mind the horse poo as there is a lot on the track) but trust me it's worth it. It took us about an hour each way while stopping and taking photos. Make sure you bring some beers to enjoy after the hike!
Time Required: 2/3 hours
Cost: free