Atacama Desert: Chile's Otherworldly High-Altitude Plateau

The Atacama Desert stretches for 1,000 kilometres along the Pacific coast of South America, between the Andes and the Chilean Coast Range, and is the driest non-polar desert on Earth. Some parts of the Atacama have never recorded rainfall in human history, and the combination of the extreme aridity, the high altitude, and the clear skies has made it one of the most extraordinary landscapes on the planet — and the site of the world's most powerful astronomical observatories.

San Pedro de Atacama, the small town at the heart of the desert, is the base for most visitors — a place of adobe houses, dusty streets, and an extraordinary concentration of natural wonders within a few hours' drive. The Valle de la Luna (Valley of the Moon), 15 kilometres from town, is a landscape of salt formations, sand dunes, and eroded rock that resembles the surface of another planet, particularly at sunset when the colours shift from white to gold to deep red.

The El Tatio geysers, at 4,320 metres in the Andes above San Pedro, are the highest geysers in the world and the third largest geyser field on Earth. The geysers are most active at dawn, when the cold air causes the steam to rise dramatically from the vents, and the combination of the geysers, the flamingos in the nearby lagoons, and the Andean peaks in the background makes for one of the finest dawn experiences in South America.

The Salar de Atacama, the largest salt flat in Chile, is home to three species of flamingo — the Chilean, Andean, and James's flamingo — that feed on the algae in the salt lakes. The Laguna Chaxa, in the centre of the salt flat, is the finest flamingo-watching spot in the Atacama, and the combination of the pink birds, the white salt, and the blue sky of the altiplano is one of the most beautiful natural images in South America.

The stargazing in the Atacama is the finest in the world — the combination of the altitude, the aridity, and the distance from light pollution produces skies of extraordinary clarity. The ALMA Observatory, the world's most powerful radio telescope array, is located in the Atacama, and the ESO's Very Large Telescope at Paranal is visible from the road between Antofagasta and San Pedro. The tour operators in San Pedro offer stargazing tours that use powerful telescopes to show the Milky Way, the Magellanic Clouds, and the planets in extraordinary detail.

The Atacama Crossing, a 250-kilometre ultramarathon through the desert, is one of the world's most extreme endurance events — seven days of running through salt flats, sand dunes, and volcanic landscapes at altitude. For those who prefer a less demanding engagement with the desert, the cycling routes between San Pedro and the surrounding attractions are excellent, and the mountain biking on the volcanic slopes above the town is some of the finest in South America.

The best time to visit the Atacama is from April to October, when the weather is dry and the temperatures are manageable. The summer months (December to March) bring the Bolivian winter — afternoon thunderstorms that can make the roads impassable and the geysers inaccessible. The winter months (June to August) are cold at night — temperatures can drop to -10°C — but the days are warm and sunny and the skies are at their clearest.

Getting to San Pedro de Atacama requires some planning. The nearest commercial airport is Calama (CJC), roughly 100 kilometres north of San Pedro, which receives domestic flights from Santiago and a small number of international connections. The drive from Calama to San Pedro takes around an hour and a half on a paved road through the desert; shared transfers and private taxis are available at the airport. Alternatively, some travellers arrive overland from Bolivia via the Uyuni salt flats, a crossing that passes through some of the most dramatic high-altitude scenery in South America, though this route requires careful planning and is not suitable in all weather conditions.

Altitude is the most important practical consideration for visitors to the Atacama. San Pedro de Atacama sits at approximately 2,400 metres, and many of the surrounding attractions — including El Tatio and the Bolivian border crossings — are above 4,000 metres. Altitude sickness (soroche) is a genuine risk, and most travel health sources recommend spending at least one full day acclimatising in San Pedro before attempting high-altitude excursions. Symptoms including headache, nausea, and fatigue are common in the first 24 to 48 hours; ascending too quickly increases the risk of more serious conditions. Consulting a doctor before travel and carrying appropriate medication is advisable.

Accommodation in San Pedro de Atacama ranges from basic hostels to high-end eco-lodges, several of which have been designed to minimise light pollution and maximise stargazing. The town is small and most accommodation is within walking distance of the central plaza and the main tour operators. Booking in advance is strongly recommended during the peak season (July and August) and around Chilean public holidays, when the town fills quickly. Outside peak season, availability is generally better, though some operators reduce their schedules in the low season.

Tours are the standard way to visit most Atacama attractions, as many sites are on private land or require four-wheel-drive vehicles to access. San Pedro has a large number of tour operators offering day trips to El Tatio, the Valle de la Luna, the Salar de Atacama, and the Lagunas Altiplanicas. Quality and pricing vary, and it is worth comparing options and reading recent reviews before booking. Some visitors choose to rent a bicycle or hire a car for the closer attractions, which gives more flexibility over timing — the Valle de la Luna at sunset, for example, is best experienced without a large group.