Roden Crater is a cinder cone in northern Arizona, about fifty miles northeast of Flagstaff, formed by an extinct volcano roughly 400,000 years ago and still preserving its original interior crater. It has become the site of James Turrell’s long-running land art project, which reworks the cone into a naked-eye observatory focused on light, sky, perception, and celestial events. Drawing on aviation, visual psychology, and ancient observatories, the project has required major excavation and construction, including the Crater Bowl and Alpha Tunnel. Despite decades of work, foundation support, and a 2019 partnership with Arizona State University, it remained unfinished and not fully open to the public as of August 2025.