Unther is the southernmost lands in Golarion. It is defined by its extreme cold, and mountainous landscape, and that it has a thin veil to the Elemental Chaos. Culturally Unther is not just one kingdom but a region that has many city states. Each of these small kingdoms is ruled by a regent most of the time, for kings cannot pass their kingdoms down by blood. The lands of Unther are harsh and the people even more so. In order to have a kingdom you must earn it. Anyone may become king of any of the vacant thrones as long as they walk through the city gates with the head of a Dragon or serpent monster on their shoulder. For in order to rule in Unther you must be a slayer of monsters.
The thin veil has also caused the mutation of some of the humans, giving birth to the Genasi race. Influenced by the Elemental Chaos has given rise to monsters of influence from that plane in the region. Trouble with Giants and Azers. Hard warfare against creatures with mastery over earth and flame. The land itself is a danger here with most being covered by the Frostfell, you could just as easily be wandering the tundra and fall through the ice only to find and underground lava stream.