Flying her own single-engine Cessna, Marilyn Bridges has photographed from the air the awe-inspiring earth works of several ancient cultures. Here are Peruvian spirals, "runways," giant animal figures carved into the earth's surface, and monoliths (including Stonehenge) as the gods would see them. Included with Bridges' stunning photographs are discussions by four leading experts on the origins of these wonders of the world.