Iceland is the land of fire and ice, and with lots and lots of hotsprings! Rekjadalur is one of my favourites because it's basically a river. The hike to get there is a short but steep 3.5 kilometer walk but won't take you longer then 1 hour.
Some things to know:
-There are no changing rooms (so don't be shy) and no restrooms. If you need to go, there is a restroom at the parkinglot.
-Go as early as possible, we got there at 8am and there were only a few other people. But by the time we left around 11am the river was FULL
-Start your hike at Reykjadalur café (there is a big parkinglot)