When "foreign country/overseas" is mentioned in fantasy/alternate world works (especially those set in inland nations), I think "huh?"

In fantasy/otherworld works, when a foreign country is written as "overseas," it makes me think "Huh?" Some people might wonder "What does that mean? What's wrong with that?" but something about it bothers me... or rather, it catches on something. That "overseas" — what does it even mean? If a work describes a foreign country as "overseas" but then writes "they traveled to the neighboring country by carriage," I think "Huh??" If you're calling a foreign country "overseas," then "Is the neighboring country connected by land so you can go there by carriage? Is there a shallow ford that only appears at low tide? Or is this a fantasy world where there's a carriage that travels over the sea or on the ocean floor!?"