Last reviewed 29 August 2026 · A three-minute read · 1–2017
Santo Stefano gathers a long reckoning of Bologna's past: a Roman execution site, a buried temple to Isis, an early medieval cemetery, Hungarian destruction, a false relic scandal, and a vanished Jewish cemetery once the largest medieval burial ground of its kind in Italy.
The short answer
Piazza del Nettuno in Bologna, Italy, sits beside Palazzo Re Enzo, where Enzo of Sardinia, son of Emperor Frederick II, was imprisoned from 1249 until his death in 1272. Nearby, Roman and medieval ruins lie beneath Biblioteca Salaborsa's glass floor, the Fontana Vecchia has stood since 1563, and the Sacrario dei Partigiani honours partisans killed in 1945.
1249
A captured prince was locked in the palace for life
You are standing on Piazza del Nettuno, at the seam between Bologna's town hall and its old law courts. Just across from you, Palazzo Re Enzo takes its name from a prince who never left it alive. Enzo of Sardinia, son of the Holy Roman Emperor Frederick II, was captured in battle and held prisoner in this palace from 1249 until his death in 1272 — twenty-three years locked up a few steps from where you're reading this.
Beneath your feet, or close to it, the ground hides another layer entirely. thirty metres away, glass floors in the Biblioteca Salaborsa let visitors look straight down into Roman and medieval ruins, the buried foundations of the city that came before this square. Bologna's history runs deep here — Etruscan, Celtic, Roman, then the Cispadane Republic, the short-lived state that first flew the Italian tricolour, born in this city in 1796.
The buildings ringing you — Palazzo del Podestà, built around 1200 as the seat of the city's magistrates, and the town hall beside it — have watched this square work as Bologna's civic heart for eight centuries. It is still that today: a place for markets, protests, and quiet afternoons, standing on stone that has seen all three.
A medieval prince spent 23 years as a prisoner in the palace across from you, and died there.
1945
Allied troops fought their way into Bologna nearby
Just south of the square, a memorial marks the Sacrario dei partigiani, a wall of photographs honoring partisans killed fighting the Nazis and fascists in World War Two. It stands close to where you're standing, a quiet counterpoint to the palace's medieval prisoner. The Battle of Bologna ended here in April 1945, when Polish troops and Allied forces retook the city after years of occupation.
Forty metres from you, the Fontana vecchia has stood since 1563, an old public fountain older than most of the buildings you'd think were ancient. It supplied water to a city that had already buried centuries of its own past beneath the pavement.
The bones of Bologna's dead are not far off either. A short walk south, the tomb of Rolandino dei Passaggeri, a 13th-century legal scholar, still stands near the Basilica di San Domenico.
1119
Leaning towers and an unfinished basilica flank the square
A few minutes east, the two leaning towers — Asinelli and Garisenda — rise over Bologna's skyline, built by rival medieval families as symbols of status. Beneath one of them, Guido Reni, one of Italy's great Baroque painters, died in a house nearby in 1642; a plaque marks the spot today.
The University of Bologna's oldest buildings sit within easy reach, where students have studied law and medicine since the 11th century. Its long shadow touches everything here — Enzo's trial, the notaries' guild hall, the whole legal culture that built this square.
South across the piazza, the Basilica of San Petronio has stood unfinished since construction began in 1390. Its facade, half brick and half marble, tells its own story of money running out and ambition outpacing patience.
-3
One city was built directly on top of another
The city sits on Pliocene clay, laid down between two and five million years ago in an ancient seabed. It is soft ground, easy to dig, which is part of why so much of Bologna's past — Roman streets, medieval cemeteries, Etruscan foundations — lies just beneath the surface rather than eroded away.
Long before Enzo's prison or the university, this was Etruscan Felsina, then a Celtic settlement called Bona, then the Roman colony of Bononia. Each layer built directly on the last, which is why archaeologists keep finding one city stacked on another every time they break ground.
Bologna grew into a free medieval commune, then a university town, then a city fought over by popes, emperors, and Napoleon's armies. The Cispadane Republic mentioned near the start of this walk was just one chapter in a much longer argument over who ruled this stretch of the Po valley.
Read the ground you are standing on
Every person, building and event in this story opens into its own dig in the app — and Strata will dig the ground under your feet instead, wherever that is, in about a minute, with every source shown.
In 305 AD, during Diocletian's persecution, Vitale and Agricola — a master and his slave — were put to death on the ground now covered by the Santo Stefano complex.
Tenth-century Hungarian raids badly damaged Santo Stefano, destroying the Church of the Holy Sepulchre, which Benedictine monks rebuilt in the 11th century.
A sarcophagus inscribed 'Symon' sparked rumors it held Saint Peter's body; the Pope had the roof torn off and the church buried in earth for seventy years to stop pilgrims diverting from Rome.
Pope Pius V ordered the destruction of a great medieval Jewish cemetery near Via Santo Stefano in 1569; its location was rediscovered by archaeologists only in 2017.
Enzo of Sardinia, son of the Holy Roman Emperor Frederick II, was held prisoner there from 1249 until his death in 1272, having been captured in battle.
What was here before Piazza del Nettuno took its current form?
The ground holds layers reaching back through Etruscan Felsina, a Celtic settlement called Bona, and the Roman colony of Bononia, with Roman and medieval ruins still visible beneath Biblioteca Salaborsa.
What is the Sacrario dei Partigiani?
It is a memorial wall of photographs honouring partisans killed fighting the Nazis and fascists in World War Two, standing close to Piazza del Nettuno.
When did the Battle of Bologna end?
It ended in April 1945, between 9 and 21 April, when Polish II Corps troops and Allied forces retook the city after years of occupation.
What was founded on this square in 1796?
The Cispadane Republic was founded there in 1796 with the backing of Napoleon's army, becoming the first Italian state to fly the tricolour flag.
How old is Palazzo del Podestà?
It was built around 1200 as the seat of Bologna's civic magistrates and stands on Piazza Maggiore beside the town hall.