A geologist researching fault lines in Greece has hypothesized that the ancient Greeks may have intentionally built their temples on fault lines, in order to expose themselves to prophetic visions caused by hallucination.
The idea of the Pythia, the high priestess at the Temple of Apollo at Delphi, inhaling hallucinatory gasses to acquire her visions is a theory that has been expounded upon for some time. In the nineteenth century, excavations led to the belief that this was not the case, but more modern excavations have suggested that there were hot springs and fault lines that could have produced hallucinatory fumes in ancient times.
But the idea that more than just the Temple of Apollo was built at this type of location is a newer idea, one which still needs some archaeological work to prove or disprove. A summary of the geologist’s article can be found here.