Mefitis is among the most distinctively Italic of the Oscan deities, with no exact Roman equivalent. Her name was attached to mephitic places across central and southern Italy, but her great cult was the open-air sanctuary at Rossano di Vaglio in Lucania, set at a crossing of cattle-tracks beside a still-flowing spring. There the surviving Oscan dedications declare that the lands and waters belong to the goddess, and pair her with other powers such as Mamers and, in syncretic form, Venus. She embodies the ambivalence of the volcanic landscape, whose rising gases could poison or cure, and she was honoured as a goddess of fertility, water and the liminal threshold between the underworld and the living surface.