Vallis: Forum-Velabrum

The flood-prone depression between Rome’s central and most history-laden hills, the *Capitoline and *Palatine, opened in the SW direction toward the *Tiber and was drained by the *Cloaca Maxima, the famed urban work of the Tarquins. Dionysius of Halicarnassus describes it as ‘the valley which extends between the Palatine and the Capitoline for a distance of about 4 stades’ (c. 700 m; Ant. Rom. 5.36.4). Starting in the area of *Subura between the *Esquiline and *Quirinal, the valley includes three topographical sub-units: the basin of the *Forum Romanum (“Forum basin”: Ammerman 213), the slight saddle of the *Velabrum, and the *Forum Bovarium area alongside the river. While the topographical unity of the valley is indisputable (see our map) and must have become obvious with every flooding (cf. Varro, Ling. 5.43; Ov., Fast. 2.391; Plut., Rom. 5.5; for the geology, Ammerman), the natural shape of the valley was veiled by the increasing functional specialization of this pivotal urban area during the Republican period, especially by the powerful architectural definition of the Forum’s S side (with the Basilica Sempronia of 169 B.C. and its successor, the *Basilica Iulia). An overarching name for the valley does not seem to be preserved from antiquity, nor has one been coined by modern scholarship. “Valle di Foro” (e.g., Coarelli 9) or “valle di Velabro” (Guiliani) have been used in passing; the term “central valley” may be even more appropriate. Together with the Circus Maximus valley, likewise drained by the Tarquins to the Tiber (*“Cloaca Circi Maximi”), and its extension into the Colosseum valley (*Vallis: Colosseum), as well as the flood plains of the *Campus Martius in the N, the *Emporium in the S, and *Trans Tiberim on the right bank, these six low-lying units form the necessary, but unlauded, complement to the celebrated Seven Hills of Rome (cf. Varro, Ling. 5.41-54).