<P> The first large - scale catacombs in the vicinity of Rome were excavated from the 2nd century onwards . They were carved through tufo , 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 . </P>
<P> The first large - scale catacombs in the vicinity of Rome were excavated from the 2nd century onwards . They were carved through tufo , 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 . </P>
where were the roman catacombs located at the time they were built
where were the roman catacombs located at the time they were built
carved through tufo , a soft volcanic rock , outside the walls of the city , because Roman law forbade burial places within city limits
carved through tufo , a soft volcanic rock , outside the walls of the city , because Roman law forbade burial places within city limits