Museum of the marble map of Rome: the Forma Urbis.
Perhaps to advertise their great civilisation, in about 203 ce the romans attached a giant 18mx13m map of Rome carved into 150 marble slabs, to the facade of a building. The facade, now of the church of st damian and cosimo, remains visible from outside the Foro Romano, but only holes in the wall remain: in medieval times , 90% of the map was destroyed for building material, leaving us only fragments dug up at various times. Reconstructing the map is a puzzle people have tried to solve for centuries: early on, for instance, Piranesi made engravings of the fragments and in 1774 his marvellous Pianta di Roma e del Campo Marzio. However, he included his own artistic interpretations of buildings which might have existed. In thec19th and 20th centuries reconstructions bevame more scientific.
But even today, only about 200 of the fragments, incised with lines representing houses, insulae, streets and public buildings, can be matched with the current city layout.
Luckily for map and urban history enthusiasts, the Museo della Forma Urbis in Rome's Celio archaeological park has tried to fit these fragments onto a giant blow-up of Noli's 1748 street map, (considrred both locationally accurate to contemporary street layout yet containing elements of the the much more ancient roman city form) .
Even then, aligning the fragments has proved difficult, as by the time of the Nolli map, most of the much larger area of ancient rome was buried under farmland.
The 18th century map and aligned 3rd century fragments are set under glass that visitors walk over: giving a powerful sense of looking through layers of time. So a reconstruction may be not be possible, but a leap of imagination via movement and participation certainly has been enabled.
As a bonus for visitors, outside the Forma Urbis museum are hundreds of roman grave sculptures and bits of buildings, with information. For instance, some cleverly fitted insides of domed ceilings; and stone columns that were shipped to Rome attached in pairs from all corners of the empire, before being finished when they arrived.
