<p>The old sanctuary to Bona Dea ‘below the Rock’ on the *Aventine, the “principal sanctuary of the region” (Coarelli), without identified remains, was of high repute (Cic., <i>Dom</i>. 136, referenced as <i>sub Saxo</i>) and reserved for women only. It was restored by Livia, in perceived emulation of Augustus’ work (Ov., <i>Fast</i>. 5.157-58: <i>restituit, ne non imitata maritum esset</i> ...; on forbidden male access: Festus 348: <i>non liceat ... in aedem Bonae Deae virum introire</i>; Macrob., <i>Sat</i>. 1.12.26 Willis; cf. Richardson 60; for the temple, probably first built under Hadrian: Chioffi 201; on the sanctuary’s possibly private status: Ziolkowski 20-21). While the precise place of the cult site is not clear, a location in Regio XII is attested by the late-antique Regionary Catalogues (<i>aedem Bonae Deae Subsaxanae</i>); further, it was situated below the mighty ‘Rock’ of its <i>mons</i>, the <i>Saxum</i> from which Remus was thought to have taken his auspices for Rome’s foundation (Ov., <i>Fast</i>. 5.149-54). For convincing reasons, the <i>Saxum</i> is identified with the cliff which forms the conspicuous N angle of the SE summit, the “Lesser Aventine” (s.v. *Remoria; contra, Ziolkowski 19), a point whose strategic importance led to its inclusion within the *Servian Wall (s.v. *Muri: Aventinus; the cliff’s extramural end was crowned, some 50 m to the S, by S. Balbina). Thus, a sanctuary right below this prominent rocky face seems warranted.</p>
<p>Uncertain, however, is whether the cult site was situated N of the cliff and thus inside the Servian Wall (Platner–Ashby, Scagnetti, Coarelli), or on the E slope and thus outside the circuit, somewhere toward the *Via Appia (Chioffi 200; Di Manzano and Quinto 69; left open by Richardson). While no revealing finds were made in either area (cf. Di Manzano and Quinto), any evidence from the N side would have been destroyed during the hasty, grand-scale building measures of the 1930s (iid. 70). The mid-Republican retaining wall along the N slope (s.v. *Aventinus: Retaining Wall) does not seem to have preserved any relevant evidence (the four wall projections, which may have indicated cult sites, shown on Lanciani, FUR pl. 41 for the segment still extant, were not observed by Di Manzano and Quinto); while emphasizing the mass of the summit as a whole, this wall was certainly not favorable to presenting the natural aspects of the Saxum, whose sheer scarp formed the constituting element of the sanctuary; thus, a location for Bona Dea on the E slope, perhaps near or within the *Horti Asiniani, may be preferable. With caution, we place an index number as close to the N point of the <i>Saxum</i> as one can come while maintaining an extramural position on the E slope.</p>