Landmannalaugar is a valley in the highlands of southern Iceland where the mountains come out orange, pink, ochre and moss green, which is not what Iceland is made of. The country is built almost entirely of dark basalt. These slopes are rhyolite, a different volcanic rock that forms when magma sits underground long enough to separate out a silica-rich melt. Steam and hot springs then oxidise the iron in it and lay sulphur over the top, and that is the paint. The same silica left the lava field at the centre of the valley as black glass. Every walk out of camp starts with you picking a line across that obsidian. Two peaks go up straight from the tents on opposite sides of it, and you have a day for one. Brennisteinsalda, the sulphur wave, is the hot one: fumaroles hiss and steam from flanks streaked red, green and ochre. Bláhnúkur is the cold one, blue-grey rhyolite whose lower paths cross ground mantled in thick, spongy moss.
The Laugavegur starts here too, the most walked trek in the country, leaving camp at the edge of the lava and climbing onto the coloured slopes with steam vents opening beside the path. Even an hour out and back puts you on the ground the through-hikers set off from. The name is older than any of the walking. It joins landmenn, the men of the Land district who drove their flocks through these mountains, with laugar, the word for warm bathing pools: the people's pools. They stopped here to rest and wash long before anyone came for the view. The heat that painted the valley does one more thing. At the edge of the lava a geothermal trickle runs into an ice-cold stream. You shuffle upstream toward the warmth or down toward the cold until the water is right, then lie back with the steam going up into the cold highland air.