Scanning the fragments of the Forma Urbis Romae
"The single most important document on ancient Roman topography is a map created in ancient times - the Forma Urbis Romae. Measuring 60 feet across, 45 feet high, and carved onto marble slabs several inches thick, it once graced the back wall of the census bureau of Rome (shown here by a yellow arrow), in the Templum Pacis. Carved between A.D. 203 and 211, during the reign of Septimius Severus, it shows every street, building, room, and staircase on the ground floor of the city - a feat of mapmaking that has never been matched. Incidentally, Il Plastico is at the same scale as the Forma Urbis, 240:1."