The landmass and the seas have been stretched and flattened Enlarge Image The Tabula Peutingeriana is one of the Austrian National Library's greatest treasures. The parchment scroll, made in the Middle Ages, is the only surviving copy of a road map from the late Roman Empire. The document, which is almost seven metres long, shows the network of main Roman roads from Spain to India. It is normally never shown to the public. The parchment is extremely fragile, and reacts badly to daylight. But it has been on display for one day to celebrate its inclusion in Unesco's Memory...