>>5634155 pb
Found something kind of sketchy in the US Embassy in Rome called a Cryptoporticus.
The cryptoporticus, a Roman underground vaulted passageway decorated by frescoes, is certainly the oldest place in the United States Tri-Mission in Rome. The corridor was one of the monuments within the summer Imperial residence of the horti Sallustiani and is dated to mid-1st century A.D.
The construction of the cryptoporticus was carried out at the time when Sallust’s gardens were included in the Imperial domain, whereas the frescoes, possibly a second phase of decoration, date to the early Severan period, between 195 and 205 A.D. The original set-up of the monument is unknown. This type of underground structure was built to connect different areas of the gardens, as well as to retain slopes and create terracing. It may have consisted of a simple gallery or could be composed of a series of parallel corridors connected to each other, or even of tri-or quadrilateral systems.
Excavations carried out in 1996-1997 brought to light two partially frescoed rooms situated opposite one another at the western end of the cryptoporticus. The access to the left room, originally a lateral branch of the cryptoporticus interrupted today by a modern wall, was blocked before the frescoed decoration was carried out and was reopened in the Renaissance period through a small door, surmounted by a fragment of a medieval sculpture in white marble (a transenna), re-used as lintel. The frescoes in this room, depicting a shrine and various decorative elements, predate those in the main passageway (end of the 1st century A.D.). A stamped brick, reconfirming the date of the cryptoporticus, was discovered in a Roman sewer in this area. An interesting partially preserved charcoal sketch from the Renaissance period, representing a Bacchic thiasos, is preserved on the higher portion of the plaster.
https://it.usembassy.gov/embassy-consulates/rome/cryptoporticus/
https://www.flickr.com/photos/ambasciatausa/sets/72157694592760034/with/40559728474/
Not many pictures so don't know if related to the Podesta Art dig, but the Bacchus reference is a hint maybe? Adrenochrome-fueled orgies held there?