Originally the catacombs where used by the first Christians as a graveyard, and also as their location for meetings and services underground. During the smaller- and larger persecutions they were forced to hide, and especially during these periods they spent much time in the catacombs beneath the streets of Rome.
In Rome they have been digging forth a total of 54 catacombs, and in these more than 7 million graves have been found. The persecutions started during Nero the Emperor, and during his days many Christians were captured, tortured and killed.
On the walls inside the catacombs pictures can be seen together with paintings and symbols, all using popular Christian symbols from those days. There are several catacombs which can be visited in Rome today, and one of these is the Saint Callixtus catacomb located by Via Appica Antica. This catacomb is open from 9.00-12.00 and from 14.00-17.00. It has an entrance fee of 8 Euro for adults, and it is closed on Wednesdays.