Milliarium
Even if they look like modern road signs showing the distance to given places, this was probably not the first function of these stone pillars. What seems more likely is that they were used to show the power of the person who erected them; some were probably used for propaganda. Very often, the inscription of the emperor was in Latin, but the inscription of the distance was in Greek. The ordinary population could probably read the second part, but not the first. Today between 7.000 and 8.000 such stones are known.