As the color of the world's largest rock changes throughout the day from orange to blue to red, many people think their eyes are playing tricks on them. Ayers Rock, known also by its aboriginal name, "Uluru," is located in a desert region of Australia known as the Red Center. Australia's native people, the Aborigines, believed this giant stone hill was a sacred dwelling for spirits that created the world. (PETE TURNER—GETTY IMAGES)