We had followed some vague directions found online, following a dirt road through a lava field, past a ruin of a house inhabited only by sheep until we came to the end of the road. And then we walked, wading across a freezing pond, before spotting a low rude wall made out of sharp edged volcanic rock. Hidden behind it, as promised, was the small hot spring. A bubble of petrified magma with the top sliced off and filled by a boiling spring. We paused, looked around and realising that we were invisible, stripped off and lowered our aching bodies into the cloudy blue-green water. It washed over my skin like a perfectly heated bath, the algae getting to work on me, smoothing out my skin, easing the muscles in my back and shoulders.