If you're looking for a unique and natural hot spring experience, Hveravellir in Iceland's central highlands is the place to be! Not only does it offer stunning geothermal fields, but there's also a beautiful natural hot spring in a warm stream where you can take a dip. The temperature is just right at 18.6-39.3 degrees C. Keep in mind that there aren't any changing facilities, but there are toilets nearby.