Also known as the Basilica Eudoxiana, it was first built in 432-440 to house the relic of the chains that bound Saint Peter when he was imprisoned in Jerusalem. According to legend, when the Empress Eudoxia (wife of Emperor Valentinian III) gifted the chains to Pope Leo I, while he compared them to the chains of St. Peter’s final imprisonment in the Mamertime Prison in Rome, the two chains miraculously fused together. The chains are kept in a reliquary under the main altar in the basilica. The basilica underwent several restorations and rebuildings, among them a restoration by Pope Adrian I, rebuilding by Pope Sixtus IV and by Pope Julius II. There was also a renovation in 1875. The front portico attributed to Baccio Pontelli was added in 1475. Michelangelo’s Moses (completed 1515), while originally intended as part of a massive 47-statue, free-standing funeral monument for Pope Julius II became the centerpiece of the Pope’s funeral monument and tomb in this, his family’s church (della Rovere family). Moses is depicted with horns, as opposed to “the radiance of the Lord”, due to the similarity in the Hebrew between the word for “beams of light” and “horns”. This kind of iconographic symbolism was common in early sacred art, and in this case was easier for the sculptor (as sculpting concrete horns is easier than sculpting rays of light) and would have been understood by all who saw it as referring to the radiance of Moses’ face; they would not have actually thought that he had horns. (http://en.wikipedia.org/wiki/San_Pietro_in_Vincoli)
This church is located very close to the Colosseum and can be seen before or after your visit there. Hotel Edera, Hotel Pace Helvezia and Hotel Gallia make it easy to stay close by.
Second day