where were the roman catacombs located at the time they were built
Catacombs of Rome The first large-scale catacombs in the vicinity of Rome were excavated from the 2nd century onwards. They were carved through tufo,[2] a soft volcanic rock, outside the walls of the city, because Roman law forbade burial places within city limits. The pagan custom was to incinerate corpses, while early Christians and Jews buried the dead. Since most Christians and Jews at that time belonged to the lower classes or were slaves, they usually lacked the resources to buy land for burial purposes. Instead, networks of tunnels were dug in the deep layers of tufo which occurred naturally on the outskirts of Rome. At first, these tunnels were probably not used for regular worship, but simply for burial and, extending pre-existing Roman customs, for memorial services and celebrations of the anniversaries of Christian martyrs. There are sixty known subterranean burial chambers in Rome. They were built outside the walls along main Roman roads, like the Via Appia, the Via Ostiense, the Via Labicana, the Via Tiburtina, and the Via Nomentana. Names of the catacombs – like St Calixtus and St Sebastian, which is alongside Via Appia – refer to martyrs that may have been buried there. About 80% of the excavations used for Christian burials date to after the time of the persecutions.[3][need quotation to verify]