Delphi

38.4824°N, 22.5010°E.

Ancient Greek sanctuary on the southwestern slope of Mount Parnassus, central Greece, occupied as a sacred site from at least 1400 BCE. The Temple of Apollo housed the Pythia, a priestess who delivered prophecies during a nine-day annual festival; the prophecies were sought by Greek city-states, foreign kings, and individuals from the 8th century BCE through 393 CE, when Theodosius I closed the oracle. Plutarch, who served as a priest at Delphi in the 1st century CE, recorded that the Pythia inhaled vapors rising through a fissure in the bedrock. Geological surveys (de Boer, Hale, Chanton, 2001) identified two intersecting bituminous limestone faults beneath the temple emitting ethylene gas — a sweet-smelling anesthetic with documented disinhibitory effects.

The Greek world consulted a single woman breathing ethylene from a crack in the bedrock for over a thousand years.