[ STELE I ] · CARRIZAL PLAYA · 31°14′06″ N
An instrument leaned to the angle of the Earth.
STELE I is a leaning cast-concrete monolith rising from a dry lakebed at thirty-one degrees north — set to true north, tilted to the obliquity, and bored so that a single shaft holds the celestial pole. It keeps the sidereal day, the solstices, and the slow drift of the pole star. The build is a hundred years long. It has only just begun.
[ 001 ] · THE SITE · 31°14′06″ N, 105°33′22″ W
Carrizal Playa
Carrizal Playa is a dry lakebed in the Trans-Pecos high desert, a flat of cracked lake clay roughly nine kilometres on its long axis, held at 1,184 metres above the sea. For most of the year it holds nothing — no standing water, no road, no light. Twice a decade a monsoon cell floods it to the depth of a hand, and it dries again to a level mirror of silt.
We did not choose it for its emptiness. We chose it for its geometry. A playa gives a true, low horizon in every direction — no ridge to clip the dawn, no canopy to break the pole. The sky above it is Bortle 2 — among the darkest that remain on the continent. On a moonless night the zodiacal light throws a shadow.
- 01Latitude — 31°14′ N
- Sets the inclination of the polar shaft. High enough to stand the celestial pole well off the horizon; low enough to give the winter sun a long, raking dawn.
- 02Horizon — playa-flat
- A true, low, unobstructed sightline to the south-eastern dawn in every direction. Nothing rises to meet the solstice sun before the aperture does.
- 03Sky — Bortle 2
- Among the darkest skies remaining in the contiguous states. The instrument is only as good as the dark it is allowed to read.
- 04Substrate — clay / caliche / bedrock
- Drained, load-bearing, and stable enough to hold a two-thousand-tonne mass to survey tolerance across centuries.
- 05Stillness — defensible custody
- Low seismicity, no development, and a tenure that can be held and watched for the length of the build and well beyond it.
[ 002 ] · GEOMETRY · TRUE NORTH
Two angles, and they are not the same angle
The slab leans 23.44° from vertical — the present obliquity of the Earth, the tilt that makes the seasons and stations the solstices. The body of the monument simply takes the posture of the world.
Bored through that leaning mass, on a true-north bearing, runs the polar shaft — inclined 31.234° above the horizon, the exact latitude of the playa. At that inclination its axis lies parallel to the axis of the Earth itself and points at the north celestial pole, the one fixed hub the entire sky turns around.
A third opening faces the dawn at azimuth 118° 42′ — the bearing at which the sun clears this horizon on the morning of the winter solstice, and on no other. True north here is found by the sun and the stars, never the needle.
The slab leans to the tilt of the Earth. The bore points to the pole. The gap between the two angles is the whole idea.
[ 003 ] · FUNCTION · WHAT IT KEEPS
Three clocks, running at three speeds
STELE I is not a sundial and not a calendar. It is a single instrument that registers three motions of the sky at once, each slower than the last — the turn of a night, the round of a year, and the precession of the pole across nearly twenty-six thousand years.
- iThe sidereal day
- 23h 56m 04.0905s — one true turn of the sky about the pole. A chosen star crosses the aperture, and 23h 56m 04s later it crosses again.
- iiThe solstices & equinoxes
- At the winter solstice the dawn beam reaches the fiducial — the year's one true tick. A south-facing meridian slot records the rest: the noon sun's cast spot rides an incised declination scale.
- iiiThe precession of the pole
- 25,772 years — the pole traces a slow circle through the stars at 50.29″ per year. STELE I is bored to the pole of its own century and built to record the drift of every century after.
| Event | When (annual) | What registers |
|---|---|---|
| Winter solstice | ≈ 21 Dec | Amber dawn beam strikes the fiducial — the year's tick |
| Vernal equinox | ≈ 20 Mar | Noon spot crosses the equinox line, ascending |
| Summer solstice | ≈ 21 Jun | Noon spot at its highest; solstice aperture in null shadow |
| Autumnal equinox | ≈ 22 Sep | Noon spot crosses the equinox line, descending |
| Every sidereal day | 23h 56m 04s | The sky completes one full turn about the polar shaft |
| Polaris closest approach | c. 2100 | Pole nearest the bore axis — 0° 27′ |
[ 004 ] · THE TICK · WINTER SOLSTICE · ≈ 21 DEC
Solstice Amber
Once a year, on the shortest morning, the sun clears the south-eastern horizon at 118° 42′ and finds the solstice aperture dead on its bearing. For a few minutes a low, hard ray rakes the length of the inner shaft and lands on a single engraved mark in the chamber wall — the fiducial. That arrival is the instrument's one true annual tick.
The beam is the only colour in the work. The concrete is grey going to weathered pale; the chamber is dim; the desert outside is bleached. But the solstice sun, dragged low and long through kilometres of dawn atmosphere, arrives the deep gold of a struck match.
The mark it lands on is a survey datum, cut to a tolerance finer than the beam is wide — the zero from which every later measurement of the pole's drift will be taken. A custodian, centuries from now, will read how far the amber has crept from the mark. That distance will be the precession, made visible.
Earned once a year, for minutes, and gone.
[ 006 ] · SECTION · CUTAWAY, LOOKING WEST
The cutaway, annotated
- AThe lean (23.44°)
- The slab off vertical. The body takes the posture of the planet; the angle the studio is named for.
- BPolar shaft
- Bored on true north, inclined 31.234° to lie parallel with Earth's axis. The night sky wheels around its opening.
- CSolstice aperture
- Cut on bearing 118° 42′ for the winter-solstice sunrise. Dark the other 364 mornings.
- DThe fiducial
- One engraved survey mark where the beam lands. The year's tick, and the zero for all later measurement of drift.
- EMeridian slot
- A thin south-facing aperture; the noon sun's cast spot rides an incised declination scale.
- FThe chamber
- The hollow interior — cool, dim, oriented. Where a custodian stands to take the annual reading.
- G·HCaisson & datum
- Reinforced footing carried 14 m to bedrock, and a leveled datum plate set flush in the floor — the instrument's structural zero.
[ 005 ] · SPECIFICATIONS · AS DESIGNED
Specifications
Planned figures unless marked. Dimensions are design intent for the completed instrument; the structure standing today is the foundation only. Angles are held to survey tolerance and corrected to true north.
| Designation | STELE I |
| Coordinates | 31° 14′ 06″ N, 105° 33′ 22″ W |
| Elevation | 1,184 m / 3,885 ft (MSL) |
| Orientation reference | True north — solar transit + GNSS baseline |
| Magnetic declination (2026.0) | 6° 49′ E — corrected out |
| Material | Cast concrete, low-heat fly-ash blend |
| Slab lean from vertical | 23.44° (the obliquity) |
| Polar shaft inclination | 31.234° above horizontal (= latitude) |
| Solstice aperture azimuth | 118° 42′ true (winter-solstice sunrise) |
| Sun declination at the tick | −23.44° |
| Height, as designed | 18.3 m / 60 ft (along the lean) |
| Mass, as designed | ≈ 2,400 t |
| Foundation depth | 14 m to bedrock |
| Sidereal day registered | 23h 56m 04.0905s |
| Precession period · rate | 25,772 years · 50.29″ / year |
| Pole–Polaris separation (2026.0) | 0° 39′, closing to 0° 27′ near 2100 |
| Custodial design horizon | ≥ 1,000 yr structural; legible ≥ 10,000 yr |
[ 007 ] · BUILD · 2023 — 2126
A hundred-year build, recently begun
As of mid-2026 the survey is complete and the foundation has just been started. There is no slab yet. There is no aperture, no fiducial, and no amber. What exists is a leveled datum plate, a verified true-north baseline, and a footing reaching toward bedrock.
The pace is the point. We do not expect to see the first verified tick. The people who will calibrate this instrument have not been born. The table is a plan, not a record of achievement — every row past the first two is a promise.
| Phase | Years | Work | Status |
|---|---|---|---|
| 00 | 2023–2026 | Survey & siting — true-north baseline, horizon profile, core sampling | Complete |
| 01 | 2026–2038 | Foundation & anchorage — caisson to bedrock, leveled datum plate | In progress |
| 02 | 2038–2071 | The casting — monolith poured in lifts, cured and settled between | Planned |
| 03 | 2071–2086 | The polar bore & solstice aperture — cut, lined, finished | Planned |
| 04 | 2086–2098 | Engraving & calibration — fiducial cut, meridian scale incised | Planned |
| 05 | Dec 2099 | First verified solstice tick (target) | Planned |
| 06 | 2100–2126 → | The Long Watch — annual observation, custodianship in perpetuity | Planned |
[ 008 ] · LINEAGE · INFLUENCE, NOT AUTHORSHIP
A lineage we did not begin
STELE I belongs to a tradition of land and light that others made before us. We claim the instrument, its geometry, and its hundred-year discipline. We claim none of the ideas that taught us a building could be aimed at the sky.
- Michael Heizer — City
- Garden Valley, Nevada. Mass and decades; proof that a work can be built at the scale of a landform and the length of a lifetime.
- Robert Smithson — Spiral Jetty
- Great Salt Lake, Utah. An earthwork married to a dry, saline basin, content to be read by the conditions of its site.
- James Turrell — Roden Crater
- Painted Desert, Arizona. A naked-eye observatory cut into a landform — light admitted, never added.
- Charles Ross — Star Axis
- Chupinas Mesa, New Mexico. The polar shaft and the precession of the pole, made walkable on foot.
- Nancy Holt — Sun Tunnels
- Great Basin, Utah. Apertures aimed precisely at the solstices — architecture as a sightline to the sky.