The Catacomb(s) of Callixtus (also known as the Cemetery of Callixtus) is one of the Catacombs of Rome on the Appian Way, most notable for containing the Crypt of the Popes (Italian: Cappella dei Papi), which once contained the tombs of several popes from the 2nd to 4th centuries.
The Catacomb is believed to have been created by future Pope Callixtus I, then a deacon of Rome, under the direction of Pope Zephyrinus, enlarging pre-existing early Christian hypogea. Callixtus himself was entombed in the Catacomb of Calepodius on the Aurelian Way. The crypt fell into disuse and decay as the relics it contained were translated from the catacombs to the various churches of Rome; the final wave of translations from the crypt occurred under Pope Sergius II in the 9th century, primarily to San Silvestro in Capite, which unlike the Catacomb was within the Aurelian Walls. The Catacomb and Crypt were rediscovered in 1854 by the pioneering Italian archaeologist Giovanni Battista de Rossi.
The arcades form part of a complex graveyard that occupies 15 hectares and is almost 20km long.
This catacomb's most ancient parts are the crypt of Lucina, the region of the Popes and the region of Saint Cecilia, where some of the most sacred memories of the place are preserved (including the crypt of the Popes, the crypt of Saint Cecilia, and the crypt of the Sacraments); the other regions are named the region of Saint Gaius and the region of Saint Eusebius (end of the 3rd century), West region (built in the first half of the 4th century) and the Liberian region (second half of the 4th century), all showing grandiose underground architecture. A modern staircase, on the site of an ancient one, was built by Pope Damasus I, giving access to the region of the Popes, in which is to be found the crypt of the popes, where nine pontiffs and, perhaps, eight representatives of the ecclesiastical hierarchy had been buried - along its walls are the original Greek inscriptions for the pontiffs Pontian, Anterus, Fabian, Lucius I and Eutychian. In the far wall Pope Sixtus II was also buried, after he was killed during the persecution of Valerian; in front of his tomb Pope Damasus had carved an inscription in poetic metre in characters thought up by the calligrapher Furius Dionisius Filocalus.