The discovery: 1940
In 1939, during construction work for the tomb of Pius XI in the crypt of St Peter's, workers accidentally broke through into an unknown underground space. Pope Pius XII authorised systematic excavations. From 1940 to 1949, a team of archaeologists — Ludwig Kaas, Bruno Apollonj Ghetti, Enrico Josi, Antonio Ferrua — explored the area beneath the basilica.
What emerged was an intact necropolis, buried when Constantine had the first basilica constructed in 320–330 AD: an entire street of the dead with multi-storey mausolea, frescoes, inscriptions, sculptures. Not an isolated tomb, but a complete Roman funerary quarter.
The necropolis: the mausolea
The street of tombs extends for about seventy metres beneath the central nave of the basilica. The mausolea are brick structures, some with two floors, datable between the first and third centuries AD. They belonged to prosperous Roman families — not necessarily Christian. Religious mixing is documented: some tombs have pagan inscriptions, others Christian, some both.
The Tomb of the Julii
The Tomb of the Julii (Mausoleum M, probably second–third century AD) is the most celebrated in the necropolis for one extraordinary iconographic detail: the ceiling is decorated with a mosaic that many scholars interpret as a representation of Christ as Sol Invictus, the Roman sun god. Christ appears on a chariot, golden rays radiating from his head, surrounded by vine tendrils. If the interpretation is correct, this is the oldest surviving Christian mosaic depicting Christ in the world.
Other mausolea
Among the most significant mausolea:
- Mausoleum of the Egyptians: frescoes with Egyptian scenes, evidence of the spread of eastern cults in Rome
- Mausoleum of the Valerians: funerary portraits of extraordinary quality
- Mausoleum of Fannia Redempta: inscriptions documenting the rank and age of the deceased
The "tropaion" of Peter
At the heart of the search was a specific structure. Around 200 AD, the ecclesiastical writer Gaius cited, in response to an opponent who boasted of the tombs of apostles in Asia, a "tropaion" — a commemorative structure — to Peter on the Vatican Hill and a "tropaion" to Paul on the Via Ostiense. The term denotes a funerary monument, not merely a venerated site.
The excavations identified, beneath the papal altar, a second-century masonry structure: the so-called aedicula, a small shrine with a niche, probably built between 160 and 180 AD above an earlier first-century burial. The ground in this area had been disturbed by subsequent interventions, including the Constantinian construction.
The Red Wall
The aedicula was built against a brick wall — the Red Wall — which the walls of the Constantinian basilica had deliberately preserved, adapting to their irregular form. This suggested that the structure had been considered sacred even before Constantine.
The bones and Margherita Guarducci
In 1953, the epigraphist Margherita Guarducci began studying graffiti incised on the so-called Graffiti Wall, a partition beside the aedicula. Among thousands of inscriptions, she identified the Greek phrase ΠΕΤΡΟΣ ΕΝΙ — Petros eni, "Peter is here" — concealed within a network of Christian graffiti and monograms.
In 1953, Guarducci also discovered that a niche in the Graffiti Wall — which should have been empty — actually contained bones, removed during the 1942 excavations and kept in a wooden box, forgotten. The bones belonged to a man of about 60–70 years of age, of robust build; they were wrapped in purple cloth interwoven with gold thread.
In 1968, Paul VI publicly announced that Peter's relics had been identified in the bones from the niche. The scientific consensus is not unanimous — DNA analysis was not technologically available and some scholars contest the identification — but the converging evidence remains historically significant.
The current layout: what you see
The Scavi tour covers roughly 150 metres beneath the basilica. Visitors enter through the Porta dei Campani (left side of the St Peter's façade) and descend gradually to necropolis level.
The circuit includes:
- The street of tombs with the flanking mausolea
- The Tomb of the Julii with the Christ-as-Sun mosaic
- The Red Wall and the aedicula
- The Graffiti Wall
- The area beneath the altar of Clement VIII (1594), built directly above the point identified as Peter's tomb
The tour ends with a visit to the Clementine Chapel, the chapel in the north transept where visitors can look down through glass at the structure of the aedicula.
How to book the Vatican Scavi
The Vatican Scavi are not part of the ordinary Vatican Museums circuit. They require:
- Direct booking through the Excavations Office of the Fabbrica di San Pietro (excavations@fsp.va)
- Advance notice: booking 2–3 months ahead is recommended in high season (April–October)
- Maximum group size: 12 people
- Duration: approximately 1.5 hours
- Cost: €13–15 per person (included in the booking)
- Guided visits only: independent visits are not permitted
Visits are held morning and afternoon, in several languages (Italian, English, German, French, Spanish).
Differences from the Vatican Grottoes
Many visitors confuse the Necropolis with the Vatican Grottoes, freely accessible from the Basilica. The Grottoes are the intermediate level, containing the tombs of popes from the fourth to the twentieth century. The Necropolis lies deeper: the Roman level, the pagan–Christian level of the first–third centuries, inaccessible without a booking.
Visiting with a private driver
The Scavi are a short walk from the main entrance to St Peter's. Arriving with a private driver allows you to manage the exact times of your booking without logistical stress.
Reach St Peter's at the precise time of your Scavi booking with a private driver. Service from €49. → Book your driver at myromedriver.com
Frequently asked questions
Are the Vatican Scavi accessible to everyone? The route includes steps, narrow corridors, and limited lighting. It is not accessible for wheelchair users. It is not recommended for children under 10 due to the length and the level of concentration required.
Are Peter's bones visible? No. The relics identified by Guarducci are kept in a reliquary beneath the papal altar. The Scavi route shows the empty niche in the Graffiti Wall.
Is there a waiting list? Yes. The Excavations Office receives requests from around the world. In high season, short-notice availability is rare. Booking 2–3 months ahead is the only reliable approach.
How deep is the necropolis relative to the current basilica? Approximately 5–10 metres beneath the floor of the present basilica. The floor of the Roman necropolis lies about 10 metres below the level of the piazza.
Is the necropolis connected to the Vatican Museums? No. It is a separate area, accessible only through the Excavations Office, not included in the Vatican Museums ticket.
Article no. 31 — TIER S — MON-02 Vatican Museums + Sistine Chapel Type: HISTORY Words: ~2,400