Barco Borghese: the Roman platform below Villa Mondragone

Driving up from Frascati to Monte Porzio Catone, you pass the Barco Borghese almost without noticing. From the road you see a wall, an avenue of olive trees and, beyond, a large flat lawn. It looks like a field. It is actually the roof of one of the largest Roman buildings in the Castelli Romani.

What is the Barco Borghese?

It is a four sided terrace of about 220 by 250 metres, looking out over the Roman countryside, in front of the entrance to Villa Mondragone. It is not a natural plateau: most of it rests on Roman substructures, a vast base of vaulted masonry rooms built to create a level surface on the side of the hill.

On top, in the Renaissance, the great Roman families who owned the Tusculan villas turned it first into a hunting reserve and then into an Italian garden, with a tufa fountain in the middle. That is where the name comes from.

Why is it called “Barco”?

“Barco” is an old form of “parco”, park: in sixteenth century villas it meant the enclosure where game was kept for hunting. “Borghese” comes from the family that owned it from the seventeenth century.

How old is it, and what is underneath?

The walls are in opus reticulatum, the Roman technique of small squared stones laid in a net pattern, which dates the building to around the middle of the first century BC, in the late Republic.

Under the terrace there are about 180 vaulted rooms (the director of the local museum network, in a 2012 interview, put the number at about 190), arranged around two parallel galleries about 137 metres long and about 8 metres high. The built area covers about 16,000 to 20,000 square metres, depending on the survey; counting the earth embankment too, the whole complex reaches about 50,000.

The north side, facing Rome, was a monumental facade marked by half columns. Probably within a century of construction parts of it collapsed: the Romans strengthened the structure with new walls and narrowed some of the vaults. In the first century AD several rooms were turned into cisterns, and in one small room there are still inscriptions painted on the plaster, linked to the storage of marble or of the marble dust used in plaster.

What was it for?

This is where certainty ends, and it is part of the Barco’s charm. The traditional reading sees it as the base of a great villa of a Roman aristocrat, like many others on the Tusculan hills. The archaeologists who have worked on it most recently point out that the plan does not look like a villa, and suggest other possibilities: a sanctuary, or a large platform with porticoes. So far none of them has been proved.

What happened after the Romans?

• Middle Ages. Excavations have found material from the eighth century: the area was never completely abandoned.
• Sixteenth century. In the second half of the century Cardinal Marco Sittico Altemps acquired the area, where Villa Tuscolana and then Villa Mondragone were built. The terrace was fenced in and became a hunting reserve; part of the substructures was used as stables.
• 1613. Cardinal Scipione Borghese, nephew of Pope Paul V, bought the Altemps properties. Villas, farmhouses and land formed the so called Burghesianum, and the Barco became an Italian garden.
• Nineteenth century. The property passed to the Jesuits and the underground galleries were rented out for growing mushrooms. The new openings did some damage, but the coating put on the walls for the mushroom beds ended up protecting them.
• Today. The site was closed to the public until 2005. After restoration, an underground route can be visited, run by the museum network of Monte Porzio Catone.

Can you visit the Barco Borghese?

Yes, on a guided tour booked in advance. The route goes down into the galleries and the Roman rooms, where you see the vaults, the original walls and the ancient writing traced on the plaster. Opening times and bookings change with the seasons and are kept up to date on the official website of the museum network.

Before or after the Barco it is worth stopping at the Museo della Città, the town museum in the old centre, which displays some of the finds from the excavations and helps you understand the setting.

In short

• Where: Via Frascati 62, Monte Porzio Catone, in front of the entrance to Villa Mondragone.
• What: an artificial terrace over about 180 Roman rooms from the first century BC; later a hunting reserve and garden of the Altemps and Borghese.
• Visits: guided, booked in advance.
• Nearby: Villa Mondragone, Tusculum, the old town.