The sanctuary lies approximately 13 kilometers west of Thebes and 4 kilometers east of Haliartos. It sits on a low ridge separating the Copais Basin from the Teneric Plain. Mount Helikon rises to the southwest and the so-called Sphinx Mountain (Phagas) to the northeast. It was this latter mountain on which the mythical sphinx dwelled, terrorizing ancient Thebes and asking Oedipus her famous riddle. The Greek traveler Pausanias used the Sphinx Mountain to orient other travelers to Onchestos and placed the sanctuary 15 stades (approximately 2.7 kilometers) from the mountain. His testimony and scant surface evidence allowed nineteenth-century travel writers and researchers like William Martin Leake and Ludwig Ross to speculate on the sanctuary’s location. In modern times, the area is called Steni Mavromatiou. The excavation area is divided into two sections designated as Site A and Site B.