The Savage Frontier

The Savage Frontier, or the North, is a harsh and untamed wilderness dotted with fortified settlements and the lairs of terrible monsters. ... [It] lies between the Sword Coast and the desert of Anauroch, extending as far north as Icewind Dale and as far south as the city of Waterdeep.

Cool, mild summers and fierce, bitter winters

Survival is a day-to-day concern

There would be value in owning parts of the land (a la countries), but between the harshness of the weather and the ever-present threat of orcs, giants, dragons, barbarians, and much much more prevent anyone from establishing anything that could be considered "borders."

It's chock full of evidence of people's efforts to tame it - from abandoned camps to frozen corpses to the ruined evidence remains of a forgotten civilization.

Examples of such civilizations:

Illefarn

Eaerlann

Delzoun

Netheril

Cities
Amphail

Waterdeep

Mirabar

Neverwinter

Peoples
Civilized Folk

Northlanders

Reghed Barbarians

Uthgardt Barbarians

Orcs

Races
Humans

Half-Orcs

Shield Dwarves

Elves

Halflings