Barco Borghese, Archaeological site in Monte Porzio Catone, Italy.

Barco Borghese is an archaeological site in Monte Porzio Catone, scenographically overlooking Rome, where a vast quadrangular esplanade rests on at least 180 vaulted rooms in concrete, built in the mid-1st century BC as the substructures of an enormous base attributed to a Roman villa. One side forms a monumental front used as a stage set for open-air performances. The visit runs along an underground route among these rooms, with epigraphic remains.

The site's vaulted substructures date to the mid-1st century BC and are traditionally linked to a Roman villa later absorbed into a large imperial estate. From 1567 the Altemps turned the quadrangular plateau into a barco, an enclosure for game. In the 17th century it was enlarged as a hunting estate, and the Borghese later laid out an Italian garden there as part of Villa Mondragone.

The name barco comes from the enclosure for wild game created by the Altemps from 1567, when the plateau became a hunting reserve. The site later passed to the Borghese and was laid out as an Italian garden, part of Villa Mondragone and the Burghesianum complex. Visitors today walk an underground route through the vaulted substructures, where epigraphic inscriptions are among the finds on display.

The visit follows an underground route through the vaulted rooms, so expect dim, cool and uneven passages; sturdy shoes and a light layer help. The site is still under restoration and study, and access is by guided tour only, so confirm current opening days and book ahead before travelling to Monte Porzio Catone.

One side of the concrete substructures forms a monumental facade that was used as a stage set for open-air performances. The site also preserves surprising epigraphic inscriptions, and it is still the object of restoration and study after a long period of abandonment.