James Turrell (born 1943) has been working with light in all its manifestations since the 1960s. Moving beyond the purely scientific investigation of optical phenomena, his works are designed to induce extraordinary experiences for the viewer, through the manipulation of light and color. The artist has been pursing this aim since 1974, when he began transforming the Roden Crater-an extinct volcano in the Arizona desert-into an observatory, inside of which visitors can immerse themselves in the embrace of an unusually pure experience of light. Turrell is currently realizing his largest installation to date in the 18-by-30-meter hall at the Kunstmuseum Wolfsburg. This work resembles the Roden Crater project, inverted and rotated 90 degrees; it thus provides a foretaste of Turrell"s still incomplete epic masterpiece. This richly illustrated publication documents and contextualizes the genesis of this extraordinary and ambitious work of art.