In the 1970s, big-name artist James Turrell made an enviable land purchase — an extinct 400,000-year-old volcanic crater about 40 miles outside Flagstaff. His vision: a naked-eye observatory and a long-lasting tribute to the desert. For decades, Turrell has wowed audiences around the world with massive installations using light and physical space. What is known about Turrell's art project/world-wonder-in-progress is the stuff of legend in the art world — mostly because very few have been invited to see it. In the Roden Crater, Turrell's apparently been building tunnels and a massive atrium that will act as both an observatory of the desert sky and as a space that captures natural light "linking visitors with the celestial movements of planets, stars, and distant galaxies." Far out.