Nancy Holt’s Land Art masterpiece will be restored.

The Dia Foundation will begin conservation efforts on Nancy Holt’s seminal earthwork Sun Tunnels (1973–76) next month. This will be the first time the work has undergone a major restorative effort since its conception 46 years ago; the conservators will primarily be focused on the erosion and cracking of the concrete that forms the tunnels.

Sun Tunnels, which Dia acquired in 2018, is located in Utah’s Great Basin Desert and composed of four cylinders, each one measuring 18 feet long and 9 feet in diameter. The cylinders are arranged on the desert floor in an X pattern that aligns them with the rising and setting sun during summer and winter solstices. Each tunnel also has a unique set of bored holes representing different constellations, which allow light and shadow to trace the Earth’s rotation throughout the day.

Jessica Morgan, director of Dia, said in a statement:

When Dia acquired Sun Tunnels in 2018, our priority was the caretaking of the artwork and the protection of Nancy Holt’s vision. With this in mind, it was imperative to make a thorough assessment of the condition of the work and ensure that any issues were addressed immediately. [. . .] These artworks each present unique and complex conservation issues, requiring vision and a deep understanding of the artists’ intentions to see these projects through.

Dia owns and maintains a great deal of artworks critical to the legacy of Land Art, including Walter De Maria’s The Lightning Field (1977) and The New York Earth Room (1977), and Robert Smithson’s Spiral Jetty (1970). It also provided initial support for the ongoing projects including James Turrell’s Roden Crater (1977–present) and Michael Heizer’s City (1972–present).

Further Reading: The Story behind “Sun Tunnels,” Nancy Holt’s Land Art Masterpiece

Further Reading: 10 Female Land Artists You Should Know