Holt's most recognized artwork, Sun Tunnels (1973–1976), is a large-scale installation in Utah's Great Basin Desert, a four-hour drive from the UMFA. It consists of four large concrete cylinders, arranged on the desert floor in a cross pattern, that align with the sunrise and sunset on the summer and winter solstices. In addition to this perfect solar framing, each of the cylinders is pierced with smaller holes representing the stars of four constellations: Draco, Perseus, Columba, and Capricorn. Holt's design allows for an ever-changing play of light and shadow upon the surfaces of her work. The four concrete tubes act as viewfinders framing precise images which, in Holt's words, "bring the vast space of the desert back to human scale."