The demolished church that survives in pieces across Milan: today you can visit its crypt

It passes almost unnoticed amid the continuous flow of tourists, commuters, and locals who cross Piazza Missori every day. We are at the intersection of Corso di Porta Romana and Via Mazzini, in the small traffic island separating the roadway from the tram tracks. Above ground, we have all seen it at least once: a brick ruin, the remains of a medieval apse.

Milanese citizens of the past used to call it “el dent cariaa” – the decayed tooth – because of its blunt, irregular shape. Below ground, however, lies the entrance to another Milan, that of Mediolanum, and to one of the city’s least-known attractions.

This is the crypt of San Giovanni in Conca, the only surviving part of the basilica of the same name demolished between 1948 and 1952, back when it still occupied the very center of Piazza Missori. Today, it can only be visited four days a month thanks to volunteers from the Touring Club Italiano (TCI), but the most fascinating aspect is that this church has not truly vanished. Its pieces are scattered all over Milan – from the Castello Sforzesco to the Pinacoteca di Brera – and tracking them down requires a genuine treasure hunt across the city.

It is eight meters wide, paved with large flagstones, and equipped with one of Milan’s earliest sewage systems. It is flanked by sidewalks, porticoes, and elegant buildings with mosaics, wells, and cisterns. This is the Decumanus Maximus, the great artery of Roman Milan that connected the city to Rome and to the Forum, located where Piazza San Sepolcro stands today. Today, its path partly coincides with the axis formed by Corso di Porta Romana, Piazza Missori, and Via Santa Maria alla Porta, and some remains are still visible in the mezzanine of the Missori subway station.

It was here, in the 5th century, that a paleochristian basilica dedicated to St. John the Evangelist was built, named “in Conca” probably due to the depression of the surrounding terrain. Around it, the Roman residential neighborhood had already disappeared, and the area had taken on a burial function. The city was rebuilding itself after the devastations of late antiquity, and the church was literally born as a necropolis over the ruins of Mediolanum.

Through raids, wars, and conquests, San Giovanni in Conca endured until the 11th century, when it was almost entirely rebuilt in the Romanesque style alongside the large crypt that we can still visit today.

Even then, however, the church was a collage of different materials and eras: the eighteen columns supporting the vaults have mismatched bases, shafts, and capitals, and among them, a Roman Corinthian capital even appears, reused upside down as a base. The destiny of San Giovanni in Conca, after all, seemed already written: to be dismantled, reused, and reassembled through the centuries.

The true golden age of San Giovanni in Conca arrived when Milan stopped being a communal city and began to envision itself as a capital. It was the era of the Visconti, the family that between the 14th and 15th centuries filled the city with castles, walls, palaces, and symbols of their power.

The building favored by the Visconti, however, was no longer the small paleochristian basilica built on the ruins of Mediolanum. Following the 11th-century Romanesque reconstruction and the restorations that succeeded the destruction by Frederick Barbarossa, San Giovanni in Conca had become a grand medieval three-nave church, complete with a transept, a central tiburio, a new marble and brick facade, and a tall bell tower. The facade was striking: a niche housed the bust of St. John the Evangelist, depicted immersed in the cauldron of boiling oil in which, according to tradition, Emperor Domitian tried in vain to martyr him.

The elegance of the building so captivated Bernabò Visconti that in the 14th century he decided to incorporate it into his own residence, the famous Ca’ di Can – so named for the fierce dogs raised by the Lord of Milan. Located practically adjacent to the noble palace, the church became the perfect stage to display the dynasty’s power. The walls were richly frescoed, the apse welcomed the equestrian monument of Bernabò sculpted by Bonino da Campione, and the crypt became the burial site for his wife, Beatrice Regina della Scala.

San Giovanni in Conca thus became the palatine chapel of the Visconti and, subsequently, of the Sforza, accompanying for nearly a hundred and fifty years the fortunes of the families ruling Milan. From meteorological observatory to roadside ruin: the long demise of San Giovanni in Conca The end of San Giovanni in Conca did not come abruptly: it spanned nearly two centuries during which Milan dismantled it bit by bit, which is perhaps why its fragments can now be found everywhere.

In 1531, Francesco II Sforza gifted it to the Carmelites of the Mantua Congregation, who built a monastery there, and in the 17th century, architect Francesco Castelli gave it a new Baroque appearance. Deconsecration arrived at the end of the 18th century, when the Austrians suppressed the Carmelite convent. At the beginning of the 19th century, closed to worship, abandoned, and stripped of its religious function, San Giovanni in Conca became first a hardware warehouse and a cart depot, and then, surprisingly, a meteorological observatory, when in 1810 Count Pietro Moscati transformed the bell tower into a tower for studying the sky.

However, when Milan decided to become a modern capital in the second half of the 19th century, introducing new road axes and large openings within the historic center, San Giovanni in Conca found itself in the wrong place. In 1877, the Municipality decided to open the new Via Carlo Alberto (now Via Mazzini) exactly where the basilica stood. After years of debate, a compromise was reached: part of the building was demolished, the presbytery and apse were rebuilt, and the medieval facade was dismantled and relocated onto the newly truncated church, positioned at an angle relative to the square. The bell tower that had hosted Moscati’s meteorological observatory was also demolished a few years later, in 1885.

From that moment on, San Giovanni in Conca was no longer a basilica but, as we see it now, a fragment. The final blow came after World War II, when “unavoidable traffic requirements” led to its complete demolition between 1948 and 1952. Only the crypt and a piece of the apse remained – that brick ruin that still emerges amid the traffic of Piazza Missori, where our story began.

Today, to see San Giovanni in Conca, it is not enough to descend into its crypt; you must literally cross the entire city and even its province. Its facade, already dismantled and relocated at the end of the 19th century, was moved once again after the post-war demolition to stand in front of the Waldensian Church on Via Francesco Sforza. The equestrian monument of Bernabò Visconti and the sarcophagus of Beatrice Regina della Scala are preserved at the Castello Sforzesco, where they still tell of the period when the basilica had become the private chapel of Milan’s most powerful family.

To see what San Giovanni in Conca looked like before the demolitions, one must visit the Pinacoteca di Brera, where Giovanni Paolo Lomazzo painted it while it was still intact, while the Museo Archeologico houses the mosaic featuring a panther, originating from the Roman neighborhood over which the basilica was built. Even the Duomo of Busto Arsizio preserves an altar from this millennial basilica. The subterranean city also holds its fragments: in the mezzanine of the Missori station, you can still see sections of the flagstones and sewage system of the Decumanus Maximus, the Roman street over which the history of this church began.

Today, the crypt of San Giovanni in Conca is a museum almost entirely devoid of artworks. The statues, altars, and even the facade have gone elsewhere. Only the columns, the bricks, and the void left by one of Milan’s oldest basilicas remain. Those who walk through it are mostly people. A select few, and only four days a month, when TCI volunteers attempt to give a voice to bare ruins that, to many, would mean nothing at all.

In fact, San Giovanni in Conca is not a lost church. It is a scattered church, sacrificed to modernity and post-war traffic. And for this very reason, it is perhaps one of the most authentically Milanese of all. To reconstruct it, going underground is not enough: you must traverse the city, look around, and imagine it as it used to be.

Featured image: Church of San Giovanni in Conca in the early 20th century, Piazza Missori, Milan. Photo via Wikimedia Commons