San Sebastiano fuori le mura (Saint Sebastian outside the walls), or San Sebastiano ad Catacumbas (Saint Sebastian at the Catacombs), is a basilica in Rome, central Italy. Up to the Great Jubilee of 2000, San Sebastiano was one of the Seven Pilgrim Churches of Rome, and many pilgrims still favor the traditional list.
The Catacombs of Rome (Italian: Catacombe di Roma) are ancient catacombs, underground burial places under or near Rome, Italy, of which there are at least forty, some discovered only in recent decades. Though most famous for Christian burials, either in separate catacombs or mixed together, they began in the 2nd century, much as a response to overcrowding and shortage of land. While past scholars have written, and much of the public today still thinks, that catacombs came about to help persecuted Christians to bury their dead secretly, this myth has been debunked: Among other reasons, catacombs always were along major highways (which would have meant they couldn't be kept secret for long), pagans also used catacombs although their religion was legal, and most catacomb building took place after Christianity's legalization. The soft volcanic tuff rock under Rome is highly suitable for tunnelling, as it is softer when first exposed to air, hardening afterwards. Many have kilometres of tunnels, in up to four stories (or layers).
The Christian catacombs are extremely important for the art history of early Christian art, as they contain the great majority of examples from before about 400 AD, in fresco and sculpture. The Jewish catacombs are similarly important for the study of Jewish art at this period.