The location of the ancient Latin city has been much debated since the 16th century. The point of departure is the foundation story in Dionysius of Halicarnassus (I.66 ff.) which speaks of a site between Monte Cavo and Lake Albano. The site has been at various times identified with the convent of S. Paolo at Palazzola, near Albano, or with Coste Caselle, near Marino, or finally with Castel Gandolfo. The last of these places in fact occupies the site of Domitian's villa, which ancient sources state in turn occupied the arx of Alba.
Archaeological data available for the Iron Age show the existence of a string of villages, each one with its own necropolis, along the south-western shore of Lake Albano. When Rome destroyed these villages they must have still been in a pre-urban phase, starting to group around a centre that may well have been Castel Gandolfo, since the necropolis there is significantly larger, suggesting a larger town.
In the later republican period the territory of Alba (the Ager Albanus) was settled once again with many residential villas, which are mentioned in ancient literature and of which remains are extant.
On the top of the Monte Cavo (Mons Albanus) was a very ancient shrine consecrated to Jupiter Latiaris. Florus (2nd century) states that the site was selected by Ascanius, who, having founded Alba, invited all the Latins to celebrate sacrifices there to Jupiter, a custom which eventually led to the annual celebration there of the Feriae Latinae, at which all the cities that belonged to the Latin Confederation would gather under the aegis of Alba, sacrificing a white bull, the flesh of which was distributed among all the participants.
After Alba Longa was destroyed and her leadership role was assumed by Rome, tradition records the building of a full-scale temple to Jupiter Latiaris on the Alban Mount in the reign of Tarquinius Superbus; of which only a few courses of perimeter wall remain today, now removed off site; and substantial remains of the paved road that connected it to the Via Appia near Aricia.