Most exploration-driven RPG campaigns have overland travel. There are many ideas on how to systematize, mechanize, and even incentivize such travel. Systemization is done via hexcrawl or pathcrawl procedures. Player-facing mechanics might incude camping mechanics, travel speed rules, or prices for a night at local inns. Incentivization includes rumors, quests, or a flyer on a tavern wall that might goad the party into action.
All of this is pretty well hashed-out, and there are robust and simple ways to handle any of the above. Hexcrawls, for instance, have been beaten to death more times than any horse. So I'm not going to talk about anything directly on the above. I want to talk about "regionalizing" your world.
Many fictional worlds have a few, or maybe many, distinct regions as part of the world. You might be able to look on a map and see that, yes, there's the swampy lands, and the treacherous mountains, and even pastoral farmland. Sometimes these work, and sometimes they all just feel transplanted from various parts of medieval Europe. I want to bring in a case study, and then discuss how to bring the good and fix the bad for an RPG world.
RuneScape has a decent-sized map. (Click to open full size).