Sources and Further Reading
Wiki
Travel Guide of Rome:
most useful and comprehensive
information includes plans of metro, trains, and buses
Catacombs
Wikipedia
Brief illustrated descriptions of all catacombs open
to the public
Churches
of Rome Wikipedia
Chronological list of some 200 churches with
Wikipedia descriptions
Recommended
further reading:
Robert Hughes "Rome", A Cultural,
Visiual, and Personal History, Alfred Knopf, 2011