Are there any other "Delphic Temple"-like sites in the world?
I recently read that, in 2001, scientists studying the Temple were able to detect ethylene gas being burped from up beneath Mt Parnassus in southern Greece. Ethylene had a brief history as anesthesia in Western medicine, in about the 1920s. However, the gas was good at knocking-out patients, but not so good for their health, it being a volatile gas. Ethylene emissions from the earth's interior seems to at least partially explain the ‘divining stupors’ of the Pythia -– the female oracle -– whom acted as Apollo’s mouthpiece.
Ethylene is sweet-smelling and “produces a narcotic effect described as a floating or disembodied euphoria.” In addition, it can cause anesthetic properties. Similar to nitrous oxide but ethylene is flammable and made up of carbon and hydrogen.
“According to traditional explanations, the Pythia derived her prophecies in a small, enclosed chamber in the basement of the temple. De Boer said that if the Pythia went to the chamber once a month, as tradition says, she could have been exposed to concentrations of the narcotic gas that were strong enough to induce a trance-like state.”
My question is, are there any other known examples of 'Vapor Cults' being based around a source of naturally emitted gases, either for shamanic/divining purposes, or just for plain narcotic reasons?
For anesthetic effects of ethylene, see: Trout, 1926. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1399426/?page=1