"Without modern mechanised transportation and confronted by enormous distances and varying weather by season, the ancient perception of distance had to have differed from our own. A long-distance journey in the Roman Empire, it has been posited, was anywhere beyond five days’ reach: quite the departure from our current ideal of anywhere not accessible within a few hours by car, plane or train."

https://aeon.co/essays/the-roman-empire-was-a-cosmopolitan-network-of-adventurers