Rock Stacking

“Rock balancing (or stone stacking, as some may call it) is an art, discipline, or hobby in which rocks are naturally balanced on top of one another in various positions. Adhesives, wires, supports, or rings are not permitted. Rock balancing can be a performance art, a spectacle, or a devotion, depending upon the interpretation by its audience. Essentially, it involves placing some combination of rock or stone in arrangements which require patience and sensitivity to generate, and which appear to be physically impossible while actually being only highly improbable”. (Wikipedia)