Sun Tunnels, Land art installation in the Great Basin Desert, Box Elder County, United States

Sun Tunnels consists of four concrete pipes, each 5.4 metres long and 2.75 metres in diameter, laid in an open X and aligned in facing pairs. The installation is 26.2 metres long. Each pipe is pierced with holes forming the constellations Draco, Perseus, Columba and Capricorn, with hole sizes varying by star magnitude.

Nancy Holt conceived Sun Tunnels in 1973 while scouting locations with her husband Robert Smithson for his Amarillo Ramp. In 1974 she bought land near the ghost town of Lucin, Utah, and construction ran from 1975 to 1976. The Dia Art Foundation purchased the work and its land in March 2018, and Holt made a film titled Sun Tunnels in 1978.

The concrete cylinders feature perforations arranged to match star constellations: Draco, Perseus, Columba, and Capricorn. Visitors experience a direct link between the structures and the night sky when looking through these openings.

Reaching the site requires a vehicle suitable for rough dirt roads, and only high-clearance or four-wheel-drive vehicles are recommended for safe travel. Visitors should bring ample water, food, and fuel, as no services exist nearby and the drive from town takes roughly an hour each way.

During summer and winter solstices, the rising and setting sun sends light through the tunnel perforations to create temporary patterns on the ground below. These annual moments reveal how the static concrete structure interacts with the sun's seasonal movement.