The catacombs around Rome are places that always fascinated visitors. Going back to the first century, Christian Romans did not have their place to bury their dead. Until Christianity's acceptance, the Ancient Romans forbade nor offered a piece of land for Christians to bury bodies in Rome. So before the catacombs, Christians and Jewish had to resort to other pagan common cemeteries. Saint Peter was buried on one on Vatican Hill in the great public 'city of the dead' (know as 'Necropolis'), and Saint Paul was buried in one along the Via Ostience.In the second century, Christians were granted small pieces of land outside of Rome's precincts and started creating subterranean burial places. It became more practical and less costly for Christians to develop underground cemetery complexes than buying open-air properties.There were about sixty catacombs near Rome, mostly along the Appian Way. The ancient Roman catacombs usually started with family tombs. Still, the newly converted Christians did not reserve places and were open for other 'brothers and sisters' in faith to be buried around the same tombs.By purchasing new land and by gifts, the catacombs eventually expanded to be impressive subterranean complexes of the dead. Sometimes a catacomb cemetery was directly managed by the new emerging Church itself for community purposes. The Saint Callistus (Callixtus) catacomb was a good example where they also put the first Roman bishops into the ground and created a Crypt of the Popes.The persecution of the early Christians was not always equally cruel and universal. There were some higher times of persecution followed by calmer, peaceful periods. During the difficult times, the catacombs were sometimes used as a temporary place to celebrate the Christian Mass and the Eucharist. However, they were not used as secret hiding places like seen in movies and novels.In 313 A.D., finally came the edict of Milan ratified by the emperors Constantine and Licinius, which gave freedom to the Church. So the Christians became free to have places of worship, build churches inside and outside of Rome and profess their faith. They could also buy properties without the fear of having these confiscated. The catacombs then became pilgrimage centers and shrines of the martyrs into all parts of the Empire.The catacombs were still used as normal cemeteries until the 5th century. Then the Church started to create basilicas for saints and martyrs and buried the dead mostly above the ground.Around the 8th to 9th century, because of repeated pillage by the Goths and Lombards barbarians, the Popes ordered to take out the catacombs' relics to place them in more secure places inside the city's churches. The catacombs then were mostly abandoned except for the Saint Pancratius and Saint Lawrence ones. Over time, vegetation and landslides blocked many catacombs' entrances and were mostly forgotten throughout the Middle Ages.It is only later, at the beginning of the 17th century, that scientific studies of the catacombs, led by Antonio Bosio, started. He was named the 'Columbus (discoverer) of the underground / subterranean Rome. Then in the 19th century was made a more systematic exploration of the catacombs by Giovanni de Rossi, who brought to light the wonders of the Saint Callistus (Callixtus) catacomb in particular. Giovanni de Rossi is known to be the founder and father of Christian Archaeology.
Priscilla, St. Agnes, St. Callixtus, St. Sebastian, and Domitilla are the five catacombs that are normally open to the public. They are open all year, except on New Year's Day, Easter and Christmas. All catacombs are closed for one day per week and one month during winter.