CLASSICAL TOPOGRAPHY
Stanford Digital Forma Urbis Romae Project
Database of all 1,186 fragments of the original marble map
Lanciani, Forma Urbis Romae
Images of Lanciani's detailed maps, published 1893-1901.
Rome Reborn
A digital model of ancient Rome.
Pompeii official website
Site in Italian and English, from the Soprintendenza Archaeologica di Napoli e Pompei.
AD 79: Destruction and Rediscovery
Maps and images of the archaeological remains of Pompeii, Herculaneum, Stabiae, Oplontis and Boscoreale.
Imago Urbis: Giuseppe Vasi's Grand Tour of Rome
High quality images and interactive maps.
I nomi antichi et moderni dell'antica citta di Roma, 1552
Rodolfo Lanciani, Pagan and Christian Rome, 1893
Available for free download from Project Gutenberg.