Cosmic images provide a useful window into the secret world of how things work. They are not reality, but they usefully consolidate values that might otherwise require whole volumes to explain. Ancient Sacred sites simply are physical locations where such images were built into a civilization. You cannot have much cultural memory without a geographical location, a sacred mountain or mound that represents the center of your world, without stars that guide the timing and direction of migrations and animal lore, myths that explain agricultural practices, or without ritual, symbols, and a set of guiding values.
