Rocca Paolina

The most remarkable thing about the Rocca Paolina is that it was meant to erase something and instead preserved it. Pope Paul III commissioned Antonio da Sangallo the Younger to build a punitive fortress on top of the Baglioni family's quarter of Perugia after the city's defeat in the Salt War of 1540 — a revolt against a new papal salt tax that ended with the city's capitulation and the pope's decision to make the consequences physically permanent. The fortress would occupy the highest point of the city, built directly over the homes and streets of the family who had run the city for decades, eliminating their district from the urban map. It stood for three centuries as the most visible symbol of papal control over Perugia. Then Perugia tore it down.

What survives is the part that was buried.

Sangallo's construction method, dictated by the terrain and the existing buildings, was not to demolish the Baglioni district but to fill it. The streets and house fronts, the tower bases and ground-floor rooms of the quarter, were filled with rubble and soil to the level of the new fortress floor, then built over. The district was sealed rather than cleared — an accidental form of preservation in which the very act of entombment kept the medieval urban fabric intact beneath the weight of the fortress above it.

When Perugia gained independence from papal control during the upheavals of 1848, the citizens attacked the above-ground portion of the fortress — a specific act of political demolition, aimed at the symbol of papal power — and dismantled most of what rose above the hillside. The underground portion was embedded in the rock below street level and could not be demolished without destroying the hill itself. It remained, sealed, until the 20th century, when the city excavated and opened the buried passages as a pedestrian route between the lower town and the upper city, installing modern escalators through the fortress passages.

The result is something that has no direct equivalent in Italy. You enter the Rocca Paolina from the lower town through an entrance cut into the hillside, and you are immediately in the buried 15th-century Baglioni quarter: actual medieval streets with house facades still standing to first-floor height, tower bases, doorways, window openings, arched passages between buildings — the entire social geography of a pre-conquest medieval urban district preserved at scale beneath the fortress that was built to erase it from collective memory. The streets are lit, signed, and maintained by the city. The escalators that carry Perugians between the lower town and Piazza Italia run through the same passages.

The Salt War that produced the fortress deserves its context. In 1539, Pope Paul III imposed a new tax on salt throughout the Papal States. The Perugians, who had a specific exemption from salt taxes under an earlier treaty, refused to pay and expelled the papal legate. The Pope's response was military force; the city capitulated in the summer of 1540 without significant fighting. The punishment Paul III chose — not execution or exile but the physical obliteration of the ruling family's district from the urban fabric — was specifically architectural. A fortress built over your houses, streets, and towers, erasing your district from the surface of the city while leaving you aware that it existed beneath: the Rocca Paolina was a form of permanent humiliation that used buildings as its medium.

The buildings below are also a social document. The Baglioni quarter preserved under the fortress contains the street plan of a 15th-century Perugian upper-class district: the relationship between the main thoroughfares and secondary lanes, the relative scale of tower houses and ordinary residences, the placement of arched passages — the spatial sociology of medieval urban life at the level of one neighborhood. Walking through it is as close as it is possible to get to the experience of walking through a medieval Italian town, with the obvious difference that it is underground, artificially lit, and serves as a commuter route for contemporary Perugians.

The guided walking tour offered through GYG (t410012, 4.7★/341 reviews, from $34) covers the underground section as part of a broader 1.5-hour Perugia historic-centre tour that also visits the Etruscan Arch, Piazza IV Novembre, and the Fontana Maggiore — one of the finest medieval fountains in Italy. The Rocca underground walk-through is free as a public pedestrian passage at any time.

[Cardaneto Castle](/castles/italy/cardaneto-castle) in Foligno, 35 kilometres southeast in the same Umbrian valley system, is the region's other medieval fortification on this site.