Restoration and enhancement works on the large exedra and the underground gallery of the Baths of Trajan on the Oppian Hill in Rome have been completed, promoted as part of the PNRR – Caput Mundi programme. The initiative restores to the city an archeological complex of exceptional significance through restoration, research, and accessibility. The project has allowed for the recovery of two 1st-century AD masterpieces: the Painted City, a fresco measuring about ten square meters with a perspective view of a fortified center, and the Great Mosaic, an imposing wall decoration depicting a theatrical setting with statues and human figures. Further excavation has also revealed previously unknown elements, such as an extra mosaic band representing buildings overlooking the sea, which is associated with the marine villa motif, as well as the remains of exquisite marble facings. To improve the guest experience, a reception area, a bookstore, a walkway above the Mosaic Hall, pedestrian walkways, picturesque rest spaces, and a new lighting system have been installed. The upper exedra has also been outfitted with a stepped auditorium for cultural performances. The public opening will take place on a trial basis on September 12th and 13th, with free guided tours on weekends, and will continue from October 2nd, Friday through Sunday, with six daily trips at limited capacity.