The Catacombs of Rome (Italian: Catacombe di Roma) are ancient catacombs, underground burial places under 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, people of all the Roman religions are buried in them, beginning in the 2nd century AD, mainly as a response to overcrowding and shortage of land. The Etruscans, like many other European peoples, used to bury their dead in underground chambers. The original Roman custom was cremation, after which the burnt remains were kept in a pot, ash-chest or urn, often in a columbarium. From about the 2nd century AD, inhumation (burial of unburnt remains) became more fashionable, in graves or sarcophagi, often elaborately carved, for those who could afford them. Christians also preferred burial to cremation because of their belief in bodily resurrection at the Second Coming. The Park of the Caffarella and Colli Albani (Rome Metro) are nearby. 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, as well as gold glass medallions (these, like most bodies, have been removed). The Jewish catacombs are similarly important for the study of Jewish culture at this period. A number of dubious relics of catacomb saints were promoted after the rediscovery of the catacombs.