The catacombs of St. Callixtus are among the greatest and most important of Rome. They originated about the middle of the second century and are part of a cemeterial complex which occupies an area of 90 acres, with a network of galleries about 12 miles long, in four levels, more than twenty meters deep.

In it were buried tens of martyrs, 16 popes and very many Christians.

They are named after the deacon Callixtus who, at the beginning of the third century, was appointed by pope Zephyrinus as the administrator of the cemetery and so the catacombs of St. Callixtus became the official cemetery of the Church of Rome.