It rained all the eighth and it did not stop once, so a hike would have been wet and cold and not worth doing.

The camper needed nothing, so there was nothing to clean and nothing to fix, and we rested. It was a welcome rest.

The ninth looked no better on paper, but we went anyway. The plan was two waterfalls in the highlands, Aldeyjarfoss and Hrafnabjargafoss.

That meant driving west along the ring road toward Mývatn. We knew the road, though not from this week. We came up into Egilsstaðir from the south a few days ago through the East Fjords, but this stretch west was the first one we drove in Iceland, almost two months ago. It felt odd to be back on it at the other end of the trip.

Past Grímsstaðir the ground changes and stays changed for a long time. This is Mývatnsöræfi, and it is lava.

It is the northern edge of Ódáðahraun, the largest unbroken lava field in Iceland, about seventeen hundred square miles of it. The name means lava of evil deeds, and it comes from a belief about outlaws. People thought the lava hid green valleys where outlaw families lived beyond the reach of the law. The name was first written down in the seventeenth century.

That belief has a long history behind it. Icelandic sagas are full of outlaws, and Grettis saga is the one that matters here. In it Grettir crosses a glacier and finds a hidden valley ringed by ice, with grass and low brush growing inside it. He decides that heat from the ground must be keeping the ice from closing over the top. The valley is called Þórisdalur, and people looked for it for centuries.

In 1664 two priests set out from Húsafell to find it, and one of them was the priest at Húsafell itself. Their account survives. They crossed the glacier, looked down into the valley, and found no hot springs, no woods, no grass and no outlaws. We camped at Húsafell in July, and we wrote then about Grettis saga and the cave at Víðgelmir.

The belief was not entirely wrong. Outlaws did live in the interior, and we have already stood beside the shelter of one. Fjalla-Eyvindur and his wife Halla lived out at Hveravellir for years in the seventeen hundreds, and his cave is still there.

The lava itself is not one eruption. The oldest out here is ten to twelve thousand years old and the youngest erupted in 2014. Most of it came from shield volcanoes, which are low broad cones that pour lava out steadily instead of blowing it up. Trölladyngja produced more of it than anything else.

The road runs flat and straight across all this. Lava, then a tuff hill, then more lava, then an old crater. Nothing grows on much of it.

There are cairns beside the road and some of them are large. A cairn is a stack of stones built by hand, and the Icelandic word is varða. Before there were roads, cairns marked the single-file tracks that crossed this country, and many still stand where the track itself has gone. They also marked farm boundaries, sea lanes and good fishing grounds.

One kind had a use we liked. A beinakerling stood beside a main route, and travellers left written verses inside it for whoever came next.

Then the road drops toward Mývatn.

We stopped at a turnout above the lake for lunch. Mývatn sits in a wide shallow basin with small islands scattered across it. The name means midge lake and in summer it earns it, but in the rain it was quiet.

From there we carried on to Fosshóll, where road 842 leaves the ring road and heads south into Bárðardalur.

Road 842 is gravel, but it was well maintained the whole way and gave us no trouble. It runs about twenty five miles south to Aldeyjarfoss.

That distance is worth sitting with. Goðafoss is right at the junction where we turned off, and there were cars and coaches there. Twenty five miles down the same valley, on the same river, we saw almost nobody.

The river is the Skjálfandafljót, the fourth longest in Iceland, and it carries both of these waterfalls as well as Goðafoss. The crowd stops at the first one and goes no further.

More links those three than the river. They all fall off the edge of one lava flow, called Bárðardalshraun. It is about nine thousand years old and it covers a hundred and seventy square miles, filling the floor of Bárðardalur from side to side, so most farms in the valley sit on it. Goðafoss drops off its outer edge at Fosshóll, and Aldeyjarfoss drops off it twenty five miles upstream where the lava meets older rock.

Aldeyjarfoss drops about sixty five feet into a canyon, and the canyon walls are basalt columns, tall and straight and packed side by side.

Basalt is cooled lava. A thick flow shrinks as it cools, and shrinking cracks it. The cracks run straight down and tend toward six sides, which is what makes the columns. Here they sit in the lower part of the flow, so the falls drop past them.

Below the falls the columns are dark grey and the water is white against them. Above the canyon rim the ground is flat and open in every direction. Gyrfalcons and merlins nest in these cliffs, along with pink-footed and greylag geese.

Hrafnabjargafoss is a couple of miles further upstream, but those two miles are on road F26 and that stretch is genuinely bad. It is the only hard part of the whole trip.

The name means raven cliffs falls, and the cliffs it is named for are the ones the lava ran up against when it came down the valley nine thousand years ago.

The falls are a different shape from Aldeyjarfoss. That one is a single drop into a slot, while this one is wide and lower, and the river splits around rock into several channels. You see the whole width of it at once.

Both sit close to the ring road and both were nearly empty. We do not have an explanation for that.

We drove back east and stopped for the night at Möðrudalur, at the farm café called Fjallakaffi. We had passed this place twice already without stopping, which was a mistake.

Möðrudalur is the highest working farm in Iceland, at about fifteen hundred feet, and the farm keeps reindeer.

Iceland has no native reindeer. They were brought from Norway between 1771 and 1787 in four separate shipments, as an attempt to start herding. The herding failed and three of the four groups died out, but the animals in the east survived and went wild. Every reindeer in the country descends from them.

We ate reindeer, and goose breast. Neither is something we get often, and both were good. Felt very weird since we just played with a rescue young reindeer just before dining.

The other reason to stop here is the view. Herðubreið stands to the south, alone on the plain, flat on top and steep on every side. It is five thousand five hundred and thirty one feet high. Icelanders call it the queen of Icelandic mountains.

Its shape comes from how it was built. It erupted underneath a glacier, and the ice held the lava in on all sides, so it piled upward instead of spreading out. There is lava on the summit, which means the eruption broke through the ice at the top. When the ice went, the mountain was left standing on its own.

Askja is next, and we go tomorrow if the rivers allow it.

That is the most challenging crossing. That is why the view from here matters more than it looks. Herðubreið stands in Ódáðahraun, and the track in to Askja runs past its foot. Askja itself sits in the same lava field, in a group of mountains called Dyngjufjöll that rise straight out of it. The 2014 eruption we mentioned this morning, the youngest lava out here, broke out just south of it.

So the ground we crossed for an hour on the ring road, the mountain we are looking at over dinner, and the crater we want to reach tomorrow are all one piece of country. We have been driving around its edge all day without going in.

The rivers on the way in have no bridges, and after this much rain the rivers matter more than the track. We will call the ranger station in the morning to check the Lindá river level.