Mýrdalssandur

Where it sits. Mýrdalssandur is the great black outwash plain on Iceland's south coast, beginning immediately east of the village of Vík í Mýrdal and running about 30 kilometres to the Kúðafljót river, with the Ring Road cutting straight across the middle of it. To the north the Mýrdalsjökull ice cap fills the horizon; to the south is open Atlantic. Between them lies a near-flat expanse of basaltic sand and gravel, mostly unvegetated, unbroken except for two isolated hills — Hafursey at 582 metres and Hjörleifshöfði at 221 metres — that stand up from the plain like ships at anchor.

How it was made. This is not a desert in any climatic sense. It is flood debris. Beneath Mýrdalsjökull sits Katla, one of the most dangerous volcanoes in Iceland, which erupts on average roughly twice a century and does so under several hundred metres of ice. Each eruption melts a colossal volume of meltwater in hours, and the resulting jökulhlaup — a glacial outburst flood — sweeps south carrying ash, sand and boulders, dumping them across the plain. The 1918 eruption pushed so much sediment out that the coastline advanced about five kilometres, creating a new southernmost point of mainland Iceland at Kötlutangi. Everything visible on Mýrdalssandur is younger than a few centuries, and the surface is rearranged by every major flood.

On screen. In September 2015 the sands beneath Hafursey and Hjörleifshöfði became Lah'mu, the farming world of the opening sequence of Rogue One: A Star Wars Story. The Erso homestead was built here on the black gravel: it is where Krennic's shuttle sets down, where Galen Erso is taken, where Lyra is killed and where Jyn hides in the bunker until Saw Gerrera finds her. The production chose the plain because it offers something almost impossible to fake — a horizon of unbroken dark ground with no vegetation, no roads and no built structures, under a sky that changes every ten minutes. Additional material for the same planet came from the black beach at Reynisfjara a few kilometres west. Nothing was left standing after the shoot; the set was struck and the surface returned to sand.

What you actually see today. Driving east from Vík, the change is abrupt: farmland stops and the land goes flat and black in the space of a kilometre. Wind moves the sand constantly, and on a clear day the plain shimmers with drifting grains at ankle height. The Múlakvísl river crosses the western end; its bridge was destroyed in July 2011 by a sudden glacial flood from Katla and was rebuilt afterwards. Marram grass and lupine have been planted in strips along the roadside to hold the sand down. Where the sand is undisturbed, it is patterned into low ridges and ripples that read like a scale model of dunes.

A practical warning about the wind. Sandstorms on Mýrdalssandur are a genuine hazard and a well-known one to Icelandic insurers, who sell specific sand-and-ash damage cover because wind-driven grit can strip the paint off a car in minutes on this stretch of the Ring Road. When the Icelandic Met Office forecasts strong easterlies or northerlies here, park facing into the wind, keep doors shut and consider delaying the drive. Visibility can drop to a few metres without warning. Driving off the marked road onto the sand is illegal everywhere in Iceland and carries heavy fines, quite apart from the near certainty of getting stuck.

Living next to Katla. The volcano under the ice is monitored continuously, and the communities around the plain rehearse for the next eruption: evacuation routes are signed along Route 1, sirens are tested, and residents know which high ground to reach. Katla has not produced a full eruption since 1918, an unusually long quiet spell by its own standards, and Icelandic authorities treat a future jökulhlaup across Mýrdalssandur as a matter of when rather than whether. Travellers crossing the plain should note the evacuation signs rather than ignore them; they are not decorative.

Timing and light. May to September gives the reliable access and the long evenings; June light at 11pm across a black plain under a pink sky is the reason photographers come here at all. Winter turns the sand into a monochrome study when snow lies in the hollows and the black ridges show through, but storms close the Ring Road with little notice. Overcast days are better than bright ones — direct midday sun flattens the plain into a featureless grey, while cloud brings out the texture.

Getting there. Vík is roughly two and a half hours east of Reykjavík on Route 1, and Mýrdalssandur begins as the road climbs out of the village. There are no services on the plain itself: no fuel, no food, no toilets, no shelter, and long stretches without mobile signal. Pull-offs exist but are informal. Vík has the nearest hotels, fuel and shops, and Kirkjubæjarklaustur, about an hour east, is the next settlement of any size.