The hidden hot river

The river was almost in sight when the trail turned to ice. One moment we were trudging up a muddy Icelandic hillside, the next we were skating in hiking boots. Steffi went down first, sliding a little way before she stopped. It was flat up there, no cliffs anywhere near us, so it was more comedy than danger, but I had the drone in my backpack and every careful shuffle came with the same thought: do not fall on the drone. We had hiked the best part of an hour to get here, there was steam rising off a river just ahead of us, and the last hundred metres were going to be the slowest of the lot.

Rewind to that morning. It was late November in Iceland, and around ten we pulled into a car park in the Reykjadalur valley, paid 6.56 euros for parking, and started walking up the hill towards a naturally hot river. That was the whole pitch: hike up a valley, find hot water at the top, get in. In an Icelandic winter, the getting in was the part we chose not to think about too hard.

The hike is supposed to take 45 minutes to an hour. It took us about that, and it felt like double, because it is uphill nearly the whole way. We broke the climb up by flying the drone over a waterfall, which was good practice for me and a good excuse to stand still for a while, and the mountains around the valley reminded Steffi of Lord of the Rings. She was not wrong. It was a valley you could imagine walking through for six months on the way to destroy some jewellery.

Then the valley started steaming. Hot springs appeared beside the trail, pools of brown boiling mud with huge bubbles the size of dinner plates breaking on the surface. Steffi walked over to one and stopped. All she could see was brown dirt, flat and ordinary, but underneath it she could hear water boiling, like a rushing river running under the ground. Warning signs stood all around: the water under there was over 80 degrees, hot enough to burn us instantly if we fell in. We got within about a metre of the edge and no closer. It is a very strange thing, standing on solid ground and hearing a river boil underneath it. It was also the best possible advertising for what was waiting further up. Somewhere above us, all that underground heat turned into a river you could actually lie in.

Which brings us back to the ice. The final stretch to the river was coated in it, and we inched across, slipping and catching ourselves, Steffi sliding down that little way, me clutching my backpack straps and thinking about the drone. It was very slow going. But after an hour of climbing, with the steam in sight, we were not turning around.

We got it wrong at first. We picked a spot too far downstream, just past where another stream joins the river, and the water there was a mix of hot and cold, warm one moment and cool the next. It was still good, in the way that any warm water is good when the air is freezing, but it was not what we had climbed for. So we got out, moved further upstream above the junction, and tried again.

Getting in was the last little slog, and honestly the hardest part of the day. We had our bathers on under our clothes, but undressing in that air was very cold, and then there was the rocky shore to cross barefoot, every stone freezing underfoot. The river is only about 50 centimetres deep, so you cannot wade in up to your neck. You have to lie down flat in it. And then the heat wraps around you all at once, like lowering yourself into a warm bath, except the bath is a river and the taps are somewhere under a volcano.

We stayed an hour, lying flat in the current with steam pouring off the surface around us. Below the water we were in the bath; above it we were still in Iceland, which is why the local advice is to wear a beanie in winter, and why it is good advice. There were a few other groups spread up and down the stream, maybe four in total, nothing like a crowd. Every so often one of us would shift position and find a cooler patch of water, then shuffle back into the warmth. We could have stayed several hours.

Then we had to get out. When I climbed out, I hung my soaked swimming shorts over a rope strung between two poles beside the river while I dried off and got into my dry clothes. Steffi got out and did the same. The whole operation took about five minutes. Then I went to pick up my shorts. They were frozen solid. Not stiff, not crunchy, frozen rigid into the exact shape I had hung them in, folded hard over an invisible rope. Five minutes. That is how long the air up there needs to freeze wet clothes solid, and that is the same air we had just spent an hour lying around in with only our heads sticking out. We laughed, and then we realised we had a problem, because I genuinely worried the shorts would snap if we forced them into the backpack. So we wrapped them in a towel and carried them back down the whole long hill: past the boiling mud, across the ice, a pair of shorts frozen into a right angle.