The Palace of Theodoric is a structure of uncertain interpretation dating back to the 7th or 8th centuries; the currently most accepted opinion is that the ruin, consisting of a body with a large portal above which a wide niche with a double window opens, corresponds to the narthex of the church of San Salvatore ad Calchi (whose last phase dates back to the 9th-10th century). In any case, the building stands in the ancient Palatine area, on the remains of the true palace of Theodoric and a previous grand building. Currently it houses inside and under the portico interesting fragments of floor mosaics found on site (1st-7th century AD).