Where did people worship Hades?

People worshipped Hades primarily in ancient Greece, where he was the god of the underworld. While he did not have many temples dedicated to him like other gods, rituals and offerings were often made at gravesites and in the context of funerary practices to honor the dead and seek favor in the afterlife. Some locations, such as the cave of Trophonius in Boeotia, were associated with him, and certain festivals, like the Anthesteria, involved honoring the spirits of the dead.