Evidence of the fortified system to defend the ‘Sacred’ in the ager Trebulanus. Memory, ruins and landscape in the Empiglione valley

[EN] The Passo della Fortuna, east of Tivoli, along the Via Empolitana, in the territory of the ancient Trebula Suffenas (the ager Trebulanus), has always had a strategic role in controlling transit along the Praeneste-Carsioli connection axis. During the Middle Ages, the pass fell along the border line of the areas of dominion of the Diocese of Tiburtina and the Sublacense Abbey. Between the end of the 10th and the beginning of the 11th century, near the Passo della Fortuna, on the opposite mountain slopes of the pass, the Rocca d’Elci and the Rocca Iuvencianum were built at the behest of the Sublacense Abbey. The two settlements adapted to and exploited the orographic particularities of the site, becoming symbolic and distinctive elements of the territory, also for the reference to the visual connection with the other fortifications. The current perception of this defensive system and the relationship that the structures, now in ruins or completely disappeared, have established with the landscape, are issues that must be considered in order not to lose the historical-cultural awareness and the memory evoked by the places.