Tabula Peutingeriana, a unique Roman road map, located at the Oesterrisches Nationalbibliothek (Austrian National Library), was on display for a day yesterday. Here is an on line version of part of the map.
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 of the World Register.
The map is orientated from East to West rather than North to South so it has a stretched appearance.
The director of the Department of Manuscripts, Autographs and Closed Collections at the Austrian National Library, Andreas Fingernagel, says it is an intensely practical document, more like a plan of the London Underground than a map.
"The red lines are the main roads. Every so often there is a little hook along the red lines which represents a rest stop - and the distance between hooks was one day's travel."
"Every so often there is a pictogram of a building to show you that there was a hotel or a spa where you could stay," he said.
"It was meant for the civil servants of the late Roman Empire, for couriers and travellers," he added.
Some of the buildings have large courtyards - a sign of more luxurious accommodation.
Details in the map indicate that while it is a 12th or 13th century map copied in Southern Germany, it probably was copied from an earlier map that dates back to the 5th century. The map includes the city of Aquileia, which was destroyed in 452 by the Huns.