Tridentum Underground Roman City (SASS)

Beneath the Piazza Cesare Battisti in central Trento lies one of the best-preserved Roman urban excavations in northern Italy, the Spazio Archeologico Sotterraneo del Sas, usually shortened to SASS. Roman Tridentum was founded as the Alpine peoples were subdued under the Emperor Augustus around 15 BC, a fortified municipium controlling the strategic Adige valley route toward the Brenner Pass. The underground site, opened to visitors after excavations in the 1990s, reveals a remarkable stretch of the ancient city preserved several metres below the modern streets. Walkways lead past a section of the Roman defensive wall and a tower, paved streets with their drainage channels, the foundations of houses and shops, mosaic and beaten-earth floors, and the remains of a porticoed road, all illuminated and interpreted in situ. The exposed layers show how the Roman town was laid out on a regular grid and how it was built up, flooded, and rebuilt over the centuries as the Adige threatened the settlement. For visitors the experience is unusually atmospheric: a self-contained slice of imperial Tridentum surviving directly under one of the city's busiest squares, reached by a stairway from street level. The site complements the cathedral's crypt and the prince-bishops' castle to tell the full story of Trento across two thousand years, from Roman frontier town through medieval bishopric to the city of the great council. Compact and weatherproof, it makes an ideal stop in any season.