Reykjadalur Thermal River

A geothermal valley where you hike 3km to reach a naturally heated river. You can actually bathe in the river — find your perfect temperature by moving between hot and cold sections.

The hike builds anticipation. Then you round a corner and steam is rising from the river. Strip down, get in, let the current flow around you. Wild bathing doesn't get better.

The name means 'smoke valley' — the steam has been rising here for millennia. It's been a bathing spot for locals since settlement times.

The hike is 3km each way, moderate difficulty. Gets muddy. No facilities — change in the open (there are wind shelters). Morning is quieter. Don't go too far upstream — water gets scalding.