Caves, rocks, springs and trees shaped ancient cult practice to a great extent and were important, sometimes legitimising components of Greek sanctuaries. They could even constitute the actual sanctuary itself. Since such natural sanctuaries were not per se precursors of later magnificent sanctuaries and an intentional natural decoration is therefore to be understood as an alternative to an architectural decoration, we will discuss what qualified natural constitutive elements as components of a sanctuary or as a sanctuary and what their function was in a sacred context on the basis of Western Asia Minor archaeological sites.