This work surveys the creation, structure, and use of the early Christian underground cemeteries around Rome, explaining how they were excavated, organized, and legally situated within contemporary burial practices. It traces their role during episodes of persecution and subsequent decline, noting shifts in funerary architecture, the veneration of saints' tombs, and the sites' long neglect and eventual rediscovery. The book examines the catacombs' paintings and sculpture, interpreting common symbols and scenes such as the Good Shepherd, baptismal and eucharistic imagery, and biblically inspired motifs. Presented as a concise guide, it gives practical orientation for visitors and directs readers to scholarly works for deeper study.