At the corner of the grounds, towards the Baths of Caracalla, under a medieval building, is the FOUNTAIN OF EGERIA. (See page 275.) _Opposite the entrance to the villa is the_ CHURCH OF SS. GIOVANNI E PAOLO, whence Cardinal Howard takes his title. It was erected in the fourth century on the site where the martyrdom of the above saints took place, by Pammachus, the friend of S. Jerome. They were officers of Constantine's household, and were put to death by Julian. The medieval portico is formed by eight marble and granite pillars. The aisles are formed by sixteen ancient columns; the pavement is of _opus Alexandrinum_; the stone surrounded by a railing is said to be that on which the martyrs suffered death. The outside of the medieval apse is rare. _To the left of the church, and beneath the adjoining Passionist Convent_ (_ring at the door on the right_), are the remains of some solid unfinished stone arches, supposed to be THE TEMPLE OF CLAUDIUS. Seutonius tells us that Vespasian erected the Temple "of Claudius on the Cœlian Mount which had been begun by Agrippina, but almost entirely demolished by Nero." Frontinus (xx. 76) tells us that the arches of Nero ended at the Temple of Claudius. Now we have been following these arches for some distance, and they end here. _Below the temple was_ THE VIVARIUM, or menagerie for the Colosseum. The arches have been laterally closed, leaving small apertures of communication. The vivarium consists of eight immense arches two stories high, formed from blocks of travertine. The substructions occupy a large extent of the convent gardens. A massive portion supports the elegant medieval campanile, of the thirteenth century, one of the best preserved in Rome. _Beneath this_ are some subterranean chambers hewn out of the tufa, supposed to be THE SPOLIARIUM, a prison for condemned gladiators. The younger Pliny says "it was a cruel receptacle for those adjudged worthy of torture." The gardens of the convent are built upon the top of THE RESERVOIR OF NERO.