The International Catacomb Society is a non-profit organization “dedicated to the preservation and documentation of the Roman catacombs & those rare vestiges of history that illustrate the common influences on Jewish, Christian, and Pagan iconography and funerary practices during the time of the Roman Empire.” It features an expanding website with already substantial resources, mostly for Rome.
While the substantial archive of images and bibliography is available only to members (dues support the goals of the organization), a substantial (and growing) number of resources are open-access. The “Vaults of Memory” online exhibit, by the Society’s founder, Estelle Shohet Brettman, contains well over one hundred slides with a rich selection of catacomb art and inscriptions accompanied by explanations; in short, excellent material for an introductory class. There is also a helpful glossary of terms; and interactive maps, which clearly situate the catacombs, along with select other monuments, including the tituli churches. An ongoing series of PDF publications on the catacombs, most by Jessica Dello Russo in the series Roma Subterranean Judaica, are also important resources. The site also includes contact information for arranging visits in Rome itself; one site, the catacombs of Priscilla, were recently renovated, and are now included in Google Earth!