Delight: deep inside a prehistorically ancient crater in the Arizona desert, artist James Turrell has created a complex series of chambers and tunnels to watch the sky and experience light.

For the last 30 years, American artist James Turrell has been at work in the Arizona desert, creating 'instruments for light' in the raw, scoured landscape. Millenni ago. a vent ripped open below what is now central Arizona, pushing up molten rock with irresistible force through a series of volcanic plugs. One of these plugs, the Roden Crater, forms the remarkable site and stage for Turrell's experiments with light and illusion. The rater is a particularly well-formed cinder cone, its rippling swell and bulk hinting slightly disturbingly at a living, organic presence beneath the desert earth. In a mammoth project that is ongoing (and not yet open to the public), Turrell has constructed a series of 'experiences of light', staged in different shaped chambers, pathways, tunnels and openings with views of the sky from within and around the surface of the crater. Part earthwork, part sculpture and part architecture, the work is on a truly Brobdingagian scale (the crater bowl is 400ft high, the equivalent of a 60-s torey building). Some spaces allow observers to measure the passage of time through the movements of planets and stars, while others celebrate the more subjective. experiential relationship between humanity and nature, through the pyrotechnic spectacle of a sunrise or sunset, or by being exposed to the different, mutable qualities of light as if it were a tangible substance.

Carved out of the geological flesh of the crater, the skycatching and skywatching spaces have a primeval intensity, as if they had been once inhabited, like the Valley of the Kings in Egypt or Chitzen Itza in Mexico, but are now an eerily vacant monument to a lost civilization. As Turrell puts it 'These things once had use. Now they are just open to the elements and you just have to feel what goes on there by the feelings that the spaces give to you'. Turrell's work fuses ancient tradition with contemporary influences--the crater is located on a working cattle ranch and the region is inflected by Native American, Western and modern cultures. Yet though monumental in conception and scale, the Roden Crater is not a monument in the conventional historic sense. Rather, it captures the drama of light, landscape, and celestial events to heighten the subjective understanding of our universe. And, like all the most moving and memorable works of art, it make us aware, with a mixture of trepidation and elation, of our place in the world. C. S.