The place
Some local researchers have put forward the hypothesis that one of the promontory's underground structures, perhaps the very Cisterna del Rospo Idolatrato, may have been reused in Roman times as a place of worship linked to the Eastern mysteries of Mithras. The hypothesis rests on comparison with other Mithraea in Lazio, such as the one discovered at Marino in 1962 inside an ancient Roman cistern that had been repurposed. For now this remains a historiographical suggestion, not confirmed by systematic excavation or by certain iconographic finds on the Circeo promontory.