Ancalagon
Dusty Dragon
there are, in a way, two challenges here. First, what about distances that take longer because the terrain is bad etc? Well, how do you measure the distance between two places with limited technology? unless you are doing a formal survey, you're going to measure by the time it takes to travel it.This doesn’t seem to account for variable travel pace?
The second is what about a particularly fast or slow traveler? Well they would learn that they cover 4 leagues in a day, or that this horse can do 12 leagues in a day for two days, but no more, etc etc.