The salt crunches underfoot like frozen snow, but the temperature exceeds thirty degrees. We are in the Valley of the Moon, a few kilometers from San Pedro de Atacama, in northern Chile, at about 2,400 meters above sea level. This geological basin owes its name to the lunar surface it mimics: white salt formations, gray clay ridges, and sculptures carved by the wind for millennia compose a landscape that resembles nothing earthly.
The valley is part of the Los Flamencos National Reserve, a protected area managed by CONAF, the Chilean forestry agency. The entrance fee is approximately between 3,000 and 5,000 Chilean pesos per person, a modest amount for what you receive in return: a silence so absolute that it becomes physically perceptible, interrupted only by the crackling of salt expanding and contracting with the thermal variations of the day.
The geology that walks
The Valley of the Moon is the result of millions of years of sedimentation in an ancient lake basin, which was then drained and uplifted by the tectonic activity of the Andes. The layers of salt, gypsum, and clay have bent and eroded to form pinnacles, natural arches, and ridges sharp as blades. Walking along the marked paths, one encounters formations that resemble solidified wax flows, others that recall compact lunar dunes, and still others that the wind has transformed into anthropomorphic figures.
One of the most surprising elements is the Salt Cave, a small cave formed within a salt deposit. The walls reflect light with millimeter crystals, creating an effect almost bioluminescent even in full daylight. It is not a spectacular cave in size, but for the quality of the material that composes it: touching it leaves the fingers white and slightly rough.
The Great Dune and the Light of Sunset
The most awaited moment of the visit takes place at the top of the Great Dune, the large dune of fine sand that dominates the western part of the valley. The climb takes about twenty minutes on slippery sand and requires some effort, especially at high altitude. The fatigue is fully rewarded: from up there, in the minutes leading up to sunset, the slanting light transforms the valley into a palette of burnt orange, dark purple, and antique pink. The shadows stretch across the clay ridges, and every relief takes on a sharp, almost theatrical profile.
This spectacle lasts less than half an hour, but it is enough to understand why dozens of visitors silently climb every afternoon, sit on the sand, and remain still without speaking. It is not politeness; it is instinct: the landscape demands a certain reverence. Bringing plenty of water is essential, as a light breeze can make the top of the dune much colder than one would expect once the sun has set.
The night in the driest desert in the world
Atacama is considered the driest non-polar desert on Earth, with some weather stations recording average annual precipitation of less than one millimeter. This extreme aridity, combined with the altitude and the almost total absence of light pollution, makes the night sky in the area among the clearest observable from the planet. Many visitors organize night astronomical tours starting from San Pedro, but even simply going out at night near the valley, without a flashlight, allows you to see the Milky Way as a three-dimensional structure, not as a flat strip.
The night silence of the Valley of the Moon is different from the daytime: denser, more definitive. There are no crickets, there are no nocturnal birds, there is no flowing water. There is only the gentle sound of the wind passing between the salt crests and, sometimes, the crackling of salt contracting with the cold. Temperatures can drop sharply after sunset, even by fifteen degrees compared to the afternoon.
How to organize the visit
San Pedro de Atacama is the mandatory starting point: the valley is about 12 kilometers from the center of the town and can be reached by bicycle along a flat dirt road in about 45 minutes, or with organized tours that depart every afternoon. The recommended arrival time is two hours before sunset, to have time to explore the main trails and then climb the Duna Mayor without haste. Avoid the central hours of the day, when the sun is at its zenith and the heat reflected by the salt becomes intense. Closed shoes with a sturdy sole are preferable to sandals, not because of the difficulty of the path but to protect the feet from the sharp edges of the salt formations along the unpaved trails.
