Other arces
The Romans also referred to the citadel of other cities as an arx (plural arces). Excavations in Cosa, Tuscany, conducted in 1948-54 and 1965-72, uncovered the settlement's arx. Frank E. Brown and his team studied the site extensively when they began the Cosa excavations in 1948. The citadel was a fortified hill on which were built several temples, including the so-called "capitolium" of Cosa.
In Lavinium, south of Rome, Castello Borghese is considered to be the possible site of the Roman arx constructed in the port city.
Read more about this topic: Arx (Roman)