The church is open all day on the 26th of December, being the saint's day. _On other days, ring the bell at the door on the right._ It is 133 feet in diameter. The outer circle consists of thirty-six columns, and the inner of twenty. There was originally another outer circle: this was destroyed, and the space between the columns of the second circle, present outer, filled in to make the walls of the church. In the centre two Corinthian columns support a cross wall. The tabernacle contains the relics of S. Stephen. The frescoes by Pomarancio on the walls, representing martyrdoms, are simply disgusting. In the vestibule is an ancient episcopal chair, from which S. Gregory read his fourth homily. _Left from the church, and left again, we enter the_ PIAZZA DI NAVICELLA. _In the piazza_ is a small marble ship, placed here by Leo X., near where it was found, this place having been the camp of the sailors. _The church opposite is that of_ S. MARIA DELLA NAVICELLA, or S. Maria in Dominica, only open on the second Sunday in Lent. It was restored by Leo X. from designs by Raphael. The Doric portico is by Michael Angelo. It has eighteen fine columns of gray granite. The mosaics in the tribune are of the ninth century. The frieze over the windows of the nave is by Giulio Romano and Pierino. _To the right of the church_ are remains of the Monastery of S. TOMMASO IN FORMIS, founded by Innocent III. as the headquarters of the Trinitarians or Redemptorists, whose mission was to rescue blacks and whites from slavery. The mosaic by Cosmati, A.D. 1260, is the coat of arms of the order. Just beyond is a Gothic arch, part of their buildings. _Beyond this_ the arch spanning the road is the ARCH OF DOLABELLA AND SILANUS. Built of travertine, and erected, as the inscription informs us, by the above consuls, A.D. 10. It was used by Nero to support the aqueduct to his reservoir. Here is the hermitage of S. Giovanni di Matha, 1213, who founded the Redemptorists. _Through the arch on the left is the entrance to_ THE VILLA CŒLIMONTANA, the residence of Baron Hoffmann, who kindly admits visitors on their leaving their cards at the iron gate. Many fragments of antiquity are spread about the grounds, from which there are some fine views. Remains have been found of a Roman fire-station of the fifth cohort of Vigili, whose names are on the pedestals dedicated by them to Marcus Aurelius. THE OBELISK was erected by Duke Mattei, but only a very small part of it is Egyptian. The fragment was found in making the present sloping way up to the Capitol, and presented by the magistrates to the duke. It is the only one not re-erected by a pope. It is said that when the architect was directing its elevation, he forgot to take his hand off the pedestal, and that the block was lowered on his hand, which was amputated, the hand being left between the blocks.