The north-western side of the court ran parallel to the Via di Venti Settembre from the Church of S. Bernardo. It contained, according to Palladio’s plan, two semicircular exedræ (LL) for philosophical conversation or disputation, and some other rooms the purpose of which is not known. The Ulpian libraries are said to have been transferred to these baths from the Forum Trajani. In this spacious court stood a great pile of buildings, the centre of which was occupied by a great hall (D), now the church of S. Maria degli Angeli. The pavement of this was raised above the ancient level of the ground by nearly eight feet, when Michael Angelo undertook to convert the ancient building into a church, and thus the bases of the columns remain buried, and new bases of stucco work have been placed round them. This roof must therefore have been in ancient times considerably more lofty than at present. The ancient roof was 120 feet high, and roofed as now, with an intersecting vault in three compartments, supported by the eight colossal ancient granite pillars. These columns of Egyptian granite with their Corinthian and composite capitals form the sole relic of the magnificence of the hall. In the modern church the transept corresponds to the longer axis of the ancient hall, and the nave to the shorter. Vanvitelli, who altered the arrangement of the church in 1749, threw out an apse for the choir on the north-east side, and made the circular laconicum (C) of the old Thermæ serve as an entrance porch. Antiquarians are not agreed as to the purpose of this great central hall. Scamozzi, in his edition of Palladio, calls it a xystus for athletic exercises, but, following the analogy of the Thermæ of Caracalla, the baths at Pompeii, and some of the other great thermæ, we should rather suppose it to have been the tepidarium. This view is confirmed when we notice that the laconicum or sudarium (C) is on one side, and the natatio (F) for the cold baths on the other, between which the tepidarium was kept at a mean temperature. The two wings of the central building were occupied by large peristylia, with cold piscinæ in the centre of each (EE). Round these peristylia were built various rooms for athletic exercises, called sphæristeria and gymnasia.