Conceptual earthwork sculpture begun in 1968; comprised of three major parts: I The Inclined Galactic Light Pond (Bamiyan, Afghanistan, 1968-1974), II The Utopic Vessel (South Pacific Ocean, Rapa Nui, 1974-1979), III The Gate into Aether, Wreath of Sounding Outer Space Above Rapa Nui, 1976-1985).