According to legend, the stone complex was built by the magician Merlin. In fact, Stonehenge appeared long before the hypothetical time of King Arthur’s companion. But how did people transport these impossibly heavy boulders from the quarry that was found hundreds of kilometers away? The construction’s purpose isn’t quite clear. Whether it was the observatory (the location of megaliths is the exact model of the solar system) or a sanctuary (that’s how Druids, the Celtic priests, used it), we might never know.