DATUM
desert · Chajnantor Plateau, Chile

Llano Observatory

23.0229° S 67.7553° W · +5,060 m

The building+5,060 m
A board-formed concrete guesthouse half sunk into a high-desert ridge beside a single telescope dome, distant snow-capped volcanoes behind.
A board-formed concrete guesthouse half sunk into a high-desert ridge beside a single telescope dome, distant snow-capped volcanoes behind.
Site
Chajnantor Plateau, Chile
Coordinates
23.0229° S 67.7553° W
Elevation
+5,060 m above sea level
Programme
Observatory and guesthouse for twelve astronomers.
Year
2026 · on site
Seed
2512851334
Field notes± 0.00 m

At five thousand metres the air holds half the oxygen of the coast and none of the light pollution. The guesthouse is sunk into the ridge so it shades itself by day, keeps its heat by night, and never casts light on the sky.

The site

A volcanic escarpment on the Chajnantor plateau, red-brown ground under an unbroken sky. The contours here fold into ridges, which is why this is the only project whose signature reads as a range.

The skin

The east screen is the most open of the four. Its density follows the ridge line, so the building is dark where the ground falls away and porous where it climbs.

Plates2 views
  1. A board-formed concrete room with a long low window at ground level framing red volcanic ground and snow-capped volcanoes.
    01Common room. The window runs at ground level along the ridge.
  2. A bronze perforated metal screen with large irregular openings set into a board-marked concrete wall above red volcanic stones.
    02East screen, bronze anodised aluminium: the most open of the four.
Building skin150 cells

A screen grown from the ground.

Face
East face
Material
Anodised aluminium, bronze
Cells
150
Opening
12% to 82% of each cell
Open overall
58%
Seed
2512851334

All four skins in the Material Library

Materials6 items

What it is made from.

  • Board-formed concrete

    Guesthouse walls and roof, cast in 240 mm lifts

    Mixed on site with cement hauled from Calama, 280 km away

  • Volcanic aggregate

    Concrete fine and coarse fraction, colour-matched to the ridge

    Excavated from the plant-room cut, screened on site

  • Anodised aluminium, bronze

    East screen, 150 cells

    Extruded in Santiago, anodised at 25 microns in Valparaiso

  • Rough-sawn Chilean pine

    Board-forming shutters, reused as sleeping-room linings

    Plantation mill in the Biobio region

  • Rammed ground insulation, 1.5 m

    Earth cover on the north and west walls

    Spoil from the ridge cut, replaced in layers

  • Dome shell, painted steel

    Telescope dome, 6 m diameter

    Fabricated in Antofagasta, assembled in 4 days at altitude
Section4 levels

Cut through the ground.

Section through Llano Observatory+3.80Dome floor+0.00Common room−3.60Sleeping−7.50Plant room
Field journal7 entries

From survey to site.

  1. Survey at 5,060 m. Crew limited to 4-hour shifts, oxygen on hand, and wind steady at 12 m/s by noon.

  2. Dark-sky readings logged for 31 nights. The ridge shields the site from the south by 4 degrees of horizon.

  3. Sunk depth settled at 8.6 m. At this level the common room sits flush with the ridge line and the plant room stays below frost.

  4. Excavation complete. 3,800 m³ moved, all of it kept for aggregate and backfill.

  5. First board-formed pour, 240 mm lift. Curing takes 9 days at this altitude, against 3 on the coast.

  6. Roof slab closed over the sleeping level. The crew is down to 22 people on site.

  7. Bronze screen panels delivered, 150 cells in 6 crates. Hanging starts when the wind drops below 8 m/s.

Next site+3,835 m

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