Here’s some Day of the Dead-worthy trivia for y’all:
During the First Temple era, the goat for Azazel was thrown down from the Temple on Yom Kippur into the Valley of Ben Hinnom (Gei Ben Hinnom, by the Cinematheque), which is also where temple cults to Moloch were built.
During the Second Temple era, the lepers were all over Gei Hinnom–that’s where Jesus went to hang with the lepers–and they changed the Azazel deposit site to the valley between the Mount of Olives and Maleh Adumim. But Gei Hinnom was still considered a (spiritually) dark and dangerous place, a karmic junkyard of sorts. By the time of the Mishnah, the this-worldly badness of Gei Hinom had become transformed into a site of otherworldy badness, that is to say: Gehennom.