Temple of Saturn
The Romans had a preference for standardization wherever possible, so Augustus, after becoming permanent commissioner of roads in 20 BC, set up the "miliarium aureum" ("golden milestone") near the Temple of Saturn. All roads were considered to begin from this gilded bronze monument. On it were listed all the major cities in the empire and distances to them. Constantine called it the "umbilicus Romae" ("navel of Rome"), and built a similar—although more complex—monument in Constantinople, the Milion.