When I visited Rome for the first time more than four decades ago, I quite randomly chose to pop in at the Museo della Civiltà Romana to see the massive model of the ancient city. The archaeologist and architect Italo Gismondi created this amazing model titled Il Plastico working at a 1:250 scale. Built between 1933 and 1937, with later expansions, the plaster city is so large that it needs to viewed  from a mezzanine above to take it all in.

Gismondi painstakingly crafted practically every then-known architectural and infrastructural feature within the walls of Rome in the Constantinian age, from 306 to 337 AD. In the fascinating video below Darius Arya points out recognizable landmarks like the Colosseum, the Forum, and the Pyramid of Cestius, as well as bridges, river fortifications, aqueducts, and even landscaping details down to the level of individual trees.