Ptahuacan was the capital city of the seven islands of Antillia, and the last surviving city of the Atlanteans by the time of the Hyborian Age. Ptahuacan was ruled by a caste of dark wizard-priests of the Hierarch of the Sacred Mysteries of Xotli. The priests ruled over the people through fear, and conducted dark rituals of mass sacrifice to their demon-god Xotli.