Valle de la Luna: Atacama Geology at Its Most Surreal

The Atacama Desert in northern Chile is the driest non-polar desert on earth. The interior plateau sits at around 2,400 metres above sea level; the cold Humboldt Current offshore suppresses moisture, and the Andes block rainfall from the east. Parts of the Atacama receive less than 1mm of rain per year. This aridity, combined with the altitude and sparse vegetation, creates a landscape that erodes into shapes that find no parallel in wetter environments.

Valle de la Luna (Moon Valley), 12km west of San Pedro de Atacama, is the concentrated expression of this. Salt flats, wind-eroded clay formations in buff and grey, amphitheatre cliffs of salt crystal, and sand dunes accumulated against the ridge walls: the combination is genuinely alien. The quality of light at sunset, when the formations turn orange and gold against a deep blue sky, is the reason every tour runs from late afternoon until dark.

Visiting Valle de la Luna

Entry to the valley costs CLP 3,500/adult (around USD $4). Tours from San Pedro run daily from approximately 16:00 to 20:00, timed for sunset. The price for a group tour (minivan with 6-12 people) is typically CLP 15,000-25,000/person. Independent car hire is straightforward if you prefer flexibility.

The valley contains several specific viewpoints. The Amphitheatre (natural rock bowl) is the main gathering point for sunset photography. The Tres Marías rock formation has three named pinnacles in eroded clay. The salt plain near the valley floor reflects light differently at different times of day.

Night visits are also possible. The Atacama sky, at altitude and with minimal light pollution, is one of the clearest on earth; the Milky Way is visible with the naked eye on clear moonless nights. Astronomy tours from San Pedro (CLP 20,000-35,000/person) use telescopes and dark-sky viewpoints within and around the valley.

San Pedro de Atacama

San Pedro is a village of around 5,000 people that exists primarily to service tourism. The streets are unpaved and the buildings are adobe; it functions as the most organised adventure tourism hub in South America. From here, day trips run to the Atacama salt flat (Salar de Atacama, with flamingos), the El Tatio geysers (highest geothermal field in the world, at 4,320 metres; departure at 04:00), Laguna Cejar (salt lake where you float on the surface), and the Valle de la Muerte.

El Tatio is the most popular tour but requires the early start; the geysers are most active in the first 2 hours after dawn because the cold morning air creates the greatest temperature differential. Tours return mid-morning after breakfast at the geyser field.

Staying in San Pedro

Accommodation ranges from backpacker hostels to high-end eco-lodges. Hostal Tulor has private rooms from CLP 50,000-80,000/night and is well-located. Explora Atacama is the luxury option: an eco-lodge with its own excursion programme, from USD $500-900/person/night all-inclusive. It’s the most expensive and most comfortable way to experience the desert.

Prices for everything in San Pedro are higher than in the rest of Chile due to the remoteness. Budget travellers: cook in hostel kitchens where possible; restaurant meals in town run CLP 8,000-15,000 for a main.

Getting There

San Pedro de Atacama is 100km from Calama and its international airport (CJC). Flights connect Calama to Santiago (2 hours). Shared transfer vehicles from Calama airport to San Pedro cost around CLP 15,000-20,000/person. The transfer to San Pedro passes through the Atacama salt flat; the landscape on the drive in sets expectations appropriately.