Italian archaeologists have made a fascinating discovery, which they announced a few days ago at a conference in Turkey where the discovery was made: the Gate to Hell, or so it is called. Officially named Pluto's Gate (Ploutonion in Greek), this portal of sorts is filled with foul-smelling fumes that cause near instant death. Also discovered was a nearby pool, which priests and such would stay in overnight to receive visions.
The visions, not surprisingly, were hallucinations caused by breathing in the diluted fumes that wafted from the Gate to Hell into the more open air. In addition to the pool discovery were stairs and a temple, as well as a column and a dedication to Kore and Pluto, lords of the underworld. The stairs are where individuals would watch the rituals performed by the priests who were allowed near the opening.
Individuals were allowed to release birds into the opening to watch them meet their quick fate, and bulls and other animals were often thrust into the opening as part of rituals, being dragged back out after dying via ropes tied to them. The opening has been discussed in many ancient texts, including by Strabo, who wrote in 24 AD: "This space is full of a vapor so misty and dense that one can scarcely see the ground. Any animal that passes inside meets instant death."
The discovery was made by Francesco D'Andria of the University of Salento, as well as his team. The portal is still as deadly today as it was thousands of years ago, according to D'Andria, who said that during the excavation process, birds were drawn towards the warm air from the opening, only to die when they got too close. For now, the team is digitally reconstructing the location, which you can see in the rendered image above.