WHERE IS UPCOUNTRY?

The word 'upcountry' is a word that's used here in Bangkok quite a lot. Basically in means anywhere outside the capital. So if I say we will be distributing our new magazine throughout Bangkok and in other cities upcountry, it means other cities throughout Thailand.
Upcountry doesn't mean anywhere north of Bangkok, which is what I first thought when I came here. Phuket, which is in the far south, is also considered to be upcountry. Confused? Now you know how I felt when I first arrived.