La Residencia - Inside the Scientists-Only Hotel in Chile's Mars-Like Desert

Location

La Residencia sits on Cerro Paranal, 120 kilometers south of Antofagasta and 110 kilometers north of Taltal, in Chile's Atacama Desert. The coordinates place it at approximately 24°38′25″S 70°23′18″W, just three kilometers from the Very Large Telescope platforms perched on the mountain summit at 2,635 meters elevation.

Getting here requires driving the Pan-American Highway before turning onto a private access road. There's no public transport, no nearby petrol stations, and the closest airport is Andrés Sabella Gálvez, about 25 kilometers from Antofagasta. The isolation is deliberate: Paranal was chosen in 1990 specifically for its exceptional astronomical conditions, including minimal cloud cover, low humidity typically between 5% and 20%, and atmospheric stability that produces some of the darkest skies on the planet.

The desert here experiences extreme temperature swings, from -8°C at night to 25°C during the day. At this altitude, reduced oxygen levels can cause fatigue and headaches for unacclimatized visitors. The Pacific Ocean lies just 12 kilometers away, though you'd hardly know it from the arid, rust-colored landscape that stretches in every direction.

ESO's Paranal Observatory

Paranal Observatory, operated by the European Southern Observatory, is the largest optical-infrared observatory in the Southern Hemisphere by total light-collecting area. Only the Mauna Kea Observatory in Hawaii surpasses it worldwide.

The flagship facility is the Very Large Telescope, consisting of four separate 8.2-meter telescopes operating in visible and infrared wavelengths. These can work together for interferometry, combining their light-gathering capacity. Four auxiliary 1.8-meter telescopes supplement the main units when needed. The site also hosts the 4.0-meter VISTA infrared survey telescope, the 2.6-meter VLT Survey Telescope, and arrays of smaller telescopes like NGTS and SPECULOOS dedicated to exoplanet hunting.

Operations run 24 hours a day, 365 days a year. Staff work eight to ten-night rotations, managing 8-12 hour shifts that demand intense concentration. The observatory's sensitivity to light pollution means everything from exterior lighting to vehicle headlamps must be carefully controlled. This scientific priority shaped La Residencia's design from the start.

Construction of the Extremely Large Telescope, located 20 kilometers east on Cerro Armazones, began in 2017 and continues as of November 2025, with first light anticipated in 2028. La Residencia now accommodates workers on that project too.

Architecture

German firm Auer Weber won an international competition in 1998 with a radical design: bury most of the hotel underground. Construction began late that year and finished in early 2002, costing approximately 12 million euros.

The L-shaped structure spans 176 by 53 meters across four levels, fitting into a natural hollow in the terrain. From a distance, the building nearly disappears. The concrete walls are tinted to match the desert's ochre hues. Only the southern and western facades emerge fully, offering views toward the Pacific Ocean.

The centerpiece is the 35-meter geodesic dome made of translucent polycarbonate panels. It covers a 1,000-square-meter tropical garden four stories deep, maintaining 35% humidity through water sprays, creating an artificial oasis where none should exist. The design incorporates curved walls and open courtyards that direct natural airflow for passive cooling, while the dome and rooftop provide solar shading.

Sustainability drove every decision. Water gets recycled for garden irrigation and the swimming pool. Natural ventilation reduces energy demands. Exterior lighting is minimized to preserve the observatory's dark skies. A 9MW solar plant operational since July 2022 now provides renewable energy to the entire complex.

The building won the LEAF Awards in 2004 for both "New Build" and "Overall" categories, then the Cityscape Architectural Review Award for best hotel in 2005. The Guardian named it one of the top ten buildings of the decade in 2009.

Inside the Complex

Astronomers return from long observation nights through this entrance, captured in one photograph as they come in to discuss the previous shift. The image shows the transition point between Paranal's harsh exterior and the climate-controlled refuge inside, where staff can finally breathe moist air and escape the desert's extreme dryness.

The interior architecture maintains the understated aesthetic of the exterior while creating distinct zones for rest and socializing.

The upper level overlooks the indoor pool, revealing the full height of the central atrium. From this vantage point, the dome's translucent panels filter natural light down through multiple floors, illuminating the tropical vegetation below.

The well-equipped interior features a pool, lush plants, and even a ping pong table, all designed to serve the needs of weary astronomers. These recreational elements transform what could be sterile institutional housing into spaces that genuinely support recovery and relaxation.

The Indoor Oasis

The huge indoor garden, featuring a swimming pool, ranks among astronomers' most beloved spaces at the facility. The pool isn't just for recreation: the water provides humidity to the otherwise bone-dry air, helping garden plants grow and preventing eyes and lips from drying out in an environment that regularly drops below 10% relative humidity

The swimming pool sits integrated into the 1,000-square-meter garden beneath the 35-meter domed roof. This humidified oasis creates a stark contrast with the surrounding Atacama aridity, offering physical recovery after demanding telescope shifts in one of Earth's most extreme environments.

The indoor garden creates a verdant refuge beneath the dome's translucent covering. Tropical plants thrive here thanks to controlled irrigation and the maintained humidity levels, providing visual relief and psychological benefits for staff working in an otherwise monochrome desert landscape.

ESO astronomers and staff members refuel at the canteen after hard days in one of the driest areas on Earth. The restaurant seats 200 people and serves international cuisine adapted for a multinational workforce, with fresh ingredients trucked 120 kilometers from Antofagasta three times daily.

The building demonstrates how modern design can adapt to extreme conditions while maintaining both functionality and aesthetic integrity.

Living and Working in the Desert

The dormitory corridors house the 108 bedrooms in quiet zones separated from the bustle of the canteen and meeting rooms. A plant peeks in from a small garden at the corridor's end, where you can sit and relax after a hard night's work at the telescopes.

Each functional bedroom measures 16 square meters with all necessary communication connections, allowing staff and visitors to work and rest efficiently. The design prioritizes essentials: private bathroom, air conditioning, and expansive windows framing views across the Atacama landscape toward the Pacific.

Open the door from your room for an inspiring view of the stars. The westward-facing windows look toward the ocean, though daytime sleep schedules mean many astronomers miss the vistas, and frequent low clouds over the Pacific often obscure the view anyway.

Even during downtime, many astronomers can't resist one more glimpse of the sky. The building was designed to minimize light pollution, preserving Paranal's exceptionally dark skies.

Located in the foothills of the observatory, the building provides respite through both its physical amenities and the psychological relief of seeing vegetation and water in an otherwise barren environment.

Looking out into the Atacama Desert, thought to be the driest place on Earth. The Mars-like terrain surrounding Paranal influenced the hotel's color scheme and material choices, with architects selecting red-tinted concrete that allows the structure to blend into its surroundings rather than stand out against them.

The Residencia offers luxurious respite from harsh working conditions, though local wildlife occasionally makes appearances, like this curious fox at breakfast.

Views from the Residencia

This spectacular shot, taken from just outside La Residencia, captures the VLT's laser guide star system in action. One Unit Telescope uses its 4 Laser Guide Star Facility to create artificial stars in Chile's night sky, exciting sodium atoms 90 kilometers above ground. The VLT uses these reference points to correct for atmospheric turbulence, delivering sharper images.

A star-strewn nighttime sky hangs over the Chilean landscape as a broken line of yellow lights weaves across dark rolling hills. These mark the route between Paranal Observatory atop Cerro Paranal and La Residencia below. The hotel was designed to minimize light pollution while preserving safe access, illustrating the constant balance between operational needs and astronomical priorities.

The facility operates under strict policies: accommodations are reserved exclusively for ESO personnel, visiting astronomers, and essential support staff. Public bookings aren't permitted. Rare exceptions include approved media representatives, as ESO did for the Quantum of Solace filming. Standard public access is limited to Saturday daytime tours at 10:00 or 14:00, which cover the observatory platform and control room but prohibit entry to La Residencia itself or any overnight stays.

For the scientists, engineers, and technicians who do stay here, rotating through eight to ten-night shifts from over 30 countries, La Residencia represents more than just accommodation. It's the difference between sustainable operation and burnout in one of the most demanding scientific environments on Earth, a deliberately designed oasis that makes world-class astronomy possible in the middle of nowhere.