Where Is the Atacama Desert? Location, Geography and How to Get There

Country, Coordinates and Borders

The Atacama Desert lies entirely within northern Chile, hugging the Pacific coast between roughly 19°S and 26°S latitude. To the north it fades into southern Peru around the city of Arica. To the east, the Andes climb sharply and form a natural wall against Bolivia and northwest Argentina, with a high-altitude border crossing at Hito Cajón near San Pedro.

To the west, a second, lower coastal mountain range separates the desert's interior from a narrow strip of shoreline and the Pacific Ocean itself.

How Big the Desert Actually Is

The Atacama's core desert covers about 105,000 km², a strip roughly 1,600 km long but rarely more than 180 km wide at any point. That makes it long and narrow rather than sprawling, closer in shape to a coastal corridor than to the wide, open expanse of the Sahara.

• Runs about 1,600 km north to south, longer than the distance from London to Rome
• Core desert area of roughly 105,000 km², similar in size to Iceland
• Rarely wider than 180 km east to west between the two mountain ranges that box it in
• Falls entirely within Chile's Antofagasta and Atacama administrative regions
• Some interior weather stations have no confirmed rainfall on record at all

San Pedro de Atacama, at 2,407 m, is the practical center of the desert for visitors and the point every distance below is measured from. Elevation climbs fast the further you travel from town, which is why most operators sequence low-altitude sights like Valle de la Luna before pushing up toward the 4,000 m-plus lagoons and volcanoes later in a trip.

The jump in altitude between town and the highlands is the single biggest planning factor. El Tatio, Cerro Toco and the Chajnantor Plateau all sit above 4,300 m, more than 1,900 m higher than San Pedro itself, which is why guided El Tatio geyser tours leave before dawn and why most itineraries save spots like the Piedras Rojas lagoon circuit for a day or two after arrival, once the body has adjusted to elevation.

A Rain Shadow on Both Sides

The Atacama is so dry because it sits in a double rain shadow. The Andes, running along the desert's eastern edge, block moist air moving in from the Amazon Basin before it ever reaches Chile. The lower coastal mountain range on the western side does the same job in reverse, catching whatever moisture drifts in off the Pacific before it can cross inland.

Squeezed between two barriers, the desert floor rarely sees a storm from either direction.

A Cold Current and a Permanent High

Offshore, the cold Humboldt Current chills the air above the Pacific enough that it cannot hold much moisture or form rain clouds in the first place, even though the ocean sits right next to the desert. A near-permanent high-pressure system parked over the southeast Pacific adds a third layer, pushing storm systems away from the coast almost year-round. Together, the two mountain ranges, the cold current and the anticyclone are why some interior weather stations have gone decades without recording measurable rain, and why the Atacama, not the Sahara, holds the title of driest nonpolar desert on Earth.

Flying In

Almost every visitor arrives through Calama's El Loa Airport (CJC), roughly a two-hour flight from Santiago on daily domestic routes. From Calama, San Pedro de Atacama is about a 100 km transfer, usually a 1.5-hour drive by shuttle, private transfer or rental car across open desert. There is no commercial airport in San Pedro itself, so Calama is the only realistic gateway by air.

Antofagasta and the Coast

Antofagasta, the regional capital and a working port city on the Pacific, sits about 300 km southwest of San Pedro, roughly a four-hour drive. It has its own international airport and works as an alternative gateway for travelers pairing a few coastal days with the desert, though the vast majority of tours still route through Calama since it sits far closer to San Pedro.

San Pedro de Atacama and its surrounding tour circuit fall inside Chile's Antofagasta Region, the country's mining heartland and the source of much of the world's copper and lithium. The village sits close enough to both Bolivia and Argentina that the borders are part of daily life here rather than an abstraction: the Hito Cajón crossing east of town is the route Bolivia-bound travelers take for a multi-day trip to the Salar de Uyuni, and the Andean peaks visible from San Pedro's plaza, including the volcano Láscar, sit inside that same tri-border zone. It is also why the Atacama stargazing tours that leave San Pedro after dark work as well as they do.

The same high altitude, dry air and distance from city lights that keep the desert bone dry also give it some of the clearest, darkest skies anywhere on the planet, which is why the ALMA Observatory's 66 antennas sit on the Chajnantor Plateau at 5,058 m rather than anywhere else in Chile.

Size is the fastest way to place the Atacama Desert next to deserts most travelers already know. At about 105,000 km², it is smaller than the Sahara by a wide margin and closer in area to Iceland, but no desert on this list matches its lack of rainfall or its altitude range, with tour stops running from 2,300 m at San Pedro up past 5,600 m on Cerro Toco.

What sets the Atacama apart isn't its footprint on a map, it's the combination of extreme dryness, high altitude and clear skies happening in the same narrow strip of land. Scientists use its soil to test Mars rover equipment for exactly this reason, and it's the same combination of altitude and clear air that makes the region such reliable ground for stargazing after dark.