A sphericon is an odd shaped three dimensional figure comprised of two cones which have been placed base to base. The entire figure is then cut down the middle from the verticies of both cones, and one of the two sides is rotated 90°. Because the cut sides of both halves are squares, the two fit back together again, and a sort of lopsided figure is formed. The resulting figure is somewhat like a möbius strip in that it only has one face - two sphericons can be rotated around each other indefinately and will always return to the point at which they started.