The desert does not begin gently. For hours you cross the stony, sunbaked country of the south, past palm oases and mud-walled towns, and then, quite suddenly, a wall of gold rises out of the flat ground ahead. These are the ergs, the true sand seas, and there are two main ones that travellers head for.

Erg Chebbi, near the town of Merzouga, is the more accessible. Its dunes rise to around 150 metres and run unbroken towards the Algerian border, close enough to reach without an expedition, which is why most desert nights happen here. Erg Chigaga, further west and reached through the frontier town of M'hamid, is larger, wilder and much harder to get to, a longer haul across rough track that rewards you with far fewer people and a deeper sense of remoteness.

Silence, cold and a sky full of stars

The first thing you notice at the camp is what you cannot hear. The desert has no hard surfaces to carry sound, no traffic, no wind in trees, often no wind at all, and the silence is total in a way that is genuinely disorienting at first. People drop their voices without meaning to. You become aware of your own footsteps in the sand.

Then the temperature turns. The desert loses its heat fast once the sun is down, and the drop can be startling, twenty degrees or more between the warmth of the afternoon and the chill of the small hours. The layers you resented carrying all day earn their place after dark, and in winter a proper warm coat is not optional. This is the detail most people get wrong before they come, imagining heat and finding cold. And then the sky. With no town for miles and nothing to drown them out, the stars come in numbers most people have never seen, the whole arch of the Milky Way laid out overhead, bright enough to throw a faint light on the sand. You lie back on a still-warm dune and simply look up. Shooting stars are common. The longer your eyes adjust, the more there are, until the sky seems less like a ceiling than a depth you are looking down into. It is the reason the desert night is worth all the driving it takes to reach it.

Desert camps range from the very simple to the surprisingly comfortable, but the shape of the evening is much the same wherever you stay. Tents are pitched in a rough circle, often in Berber style, with rugs and low seating, and at the centre there is a fire. Dinner is usually a tagine, the slow-cooked stew that arrives under its conical lid, eaten around the fire as the last light goes. The food is simple and good, cooked over gas or coals in the middle of nowhere, and it tastes the better for the setting. Afterwards, at many camps, someone brings out drums, and the crew and guests fall into the rhythm of Berber desert music, the beat carrying out into the dark.

Later the camp goes quiet. Some people turn in to their tents, others stay out on the sand with the fire burning down, reluctant to waste the sky. Sleeping in the desert is its own experience, in the deep hush, sometimes under canvas, sometimes with the tent open to the stars. It can be cold, and the ground is firmer than it looks, but waking in the night to that silence and stepping out under the stars is part of what you came for. Few people sleep straight through, and fewer regret being awake for it.

Sunrise over the sand

The desert asks to be seen at dawn, and it is worth the early start. Before the sun is up, climb a nearby dune. It is slow, hard work, two steps up and one sliding back in the soft sand, and you reach the crest with burning legs just as the light begins. Then the show. The low sun comes across the dunes almost horizontally, and for a few minutes it rakes the ridges, throwing one face into deep shadow and lighting the other a burning orange, so that the whole field stands out in sharp relief. The wind-carved patterns on the sand, the long clean lines of the crests, the ripples underfoot, all of it is at its most dramatic in that brief window before the sun climbs and flattens everything into glare.

Look closely and the desert is not as empty as it seemed in the dark. The night's tracks are written across the sand, the trails of beetles, lizards and small mammals that come out in the cool, and here and there a stubborn desert plant. From a high dune the scale finally registers, the sand running to the horizon in every direction, and you understand that the camp was only ever at the very edge of it. By mid-morning the heat is building and the first day visitors are arriving, and it is time to walk back down. But that first hour on the dune, cold, quiet and alone with the light, is the other half of the desert night, and the two together are the whole experience.