Kerlingarfjöll

Steam vents hiss through cracked orange earth and the air is all sulphur and iron on the tongue. Kerlingarfjöll is a cluster of rhyolite peaks where geothermal heat warps the colour spectrum — rust, amber, ochre and bone white streaked across mountains that look like they belong to another planet.

Kerlingarfjöll centres on Hveradalir, a geothermal valley at around a thousand metres where hot springs, fumaroles and mud pots cluster among rhyolite stained into vivid bands of orange, red and yellow — a palette intensified by the steam that drifts permanently across it. Marked trails thread the vents (the crust off-path is thin, and the paths are the deal), snow lingers in the shaded gullies well into August, and a mountain lodge at the base puts beds inside the geothermal zone itself — a rarity in the highlands. The way in is the Kjölur route, Iceland's oldest interior track, crossing the plateau between the Langjökull and Hofsjökull ice caps in the summer season.