As a result of the archaeological discoveries made between 1998 and 1999 in the gallery beneath the southwestern corner of the Baths of Trajan on the Oppian Hill (that included among other finds the building with the fresco “Painted City” and the wall mosaic “Muse and Philosopher”), excavations and restorations are at present in progress in the Baths above the gallery, in order to render them waterproof.
These excavations confirmed the presence of a large portico that ran along the inside of the entire western side of the Baths, exactly above the gallery. A few bases in travertine in the perimeter wall are all that remain of the portico’s columns. There is no trace of the pavement above the extrados of the vault. The room formed by the southwestern exedra is commonly known as the “Great Library” because of the presence of two superimposed orders of niches. This room opened onto the portico, through a columned entranceway. A test excavation inside the exedra revealed three low concentric stairs on the inside perimeter, with ample remains of marble veneers. Another portico, of smaller dimensions and with smaller column bases, was discovered on the southern front of the Baths. Excavations are in progress on the western external part of the portico, where the stratigraphy of the Trajanic construction deposits is being investigated. (Giovanni Caruso-Rita Volpe)