Meicine wheels, or sacred hoops, were constructed by laying stones in a particular pattern on the ground. Most medicine wheels follow the basic pattern of having a center of stone(s), and surrounding that is an outer ring of stones with "spokes", or lines of rocks radiating from the center. Some ancient types of sacred architecture were built by laying stones on the surface of the ground in particular patterns common to aboriginal peoples. Originally, and still today, medicine wheels are stone structures constructed by certain indigenous peoples of North America for various astronomical, ritual, healing, and teaching purposes. Medicine wheels are still 'opened' or inaugurated in Native American spirituality where they are more often referred to as "sacred hoops", which is the favoured English rendering by some. There are various native words to describe the ancient forms and types of rock alignments. One teaching involves the description of the four directions. More recently, syncretic, hybridized uses of medicine wheels, magic circles, and mandala sacred technology are employed in New Age, Wiccan, Pagan and other spiritual discourse throughout the World. The rite of the sacred hoop and medicine wheel differed and differs amongst indigenous traditions, as it now does between non-indigenous peoples, and between traditional and modernist variations. The essential nature of the rite common to these divergent traditions deserves further anthropological exploration as does an exegesis of their valence.