A bickering cluster of warring principalities and savage wilderlands, home to many of the "monstrous" races. The term "Goblin" is often used as a catch-all for many types of nonhuman races, and the lands to the north should not be considered to be populated entirely - or even primarily - by the short, green-skinned humanoids that also go by that name.
And, in truth some tribes shade into orange or brown. There are also Hyena and Dog-faced 'Goblins' and humanoids that bear mixtures of features from more than one 'monstrous' race.
Humans of the South lazily call them all 'Goblins', sometimes going as far as 'Greater Goblins' for some of the bigger varieties.
The land where it verges on the Human Kingdoms of the South is trackless rolling hill country. There are lots of small dells and little hillocks. And there are boulders and rock formations everywhere. According to sages these were gouged forth from the ground by great ice sheets many thousands of years in the past.
Navigating this trackless country is a challenge. The 'Goblins' have a system of waystones to aid them in crossing these badlands to reach the Human realms in the South. These stones were erected hundreds of years ago by an organization known as the Wayfinders Guild. Humans say that the stones were their doing and 'Goblins' tell a different story. The 'Goblin' Wars erased the true tale and covered it up with legends. There are still men and 'Goblins' who claim to have the magic swords, passed down for generations, that are necessary to find the ways from one stone to the next. With such a sword in hand a Wayfinder is said to be able to 'read' the stone and thus find the direction to take to reach the next one.
The 'Goblin' Wars also left the southern marches of the Goblin Kingdoms a nearly uninhabited wilderness. Abandoned keeps, slighted hill forts, clusters of tumbled down delvings, and crumbled wathtowers sprinkle the landscape. There are more numerous 'Goblin' tribes and strongholds in better repair the further North you go within the Kingdoms.
There are three typical kinds of strongholds, but in the Northern reaches of the 'Goblin' lands it is not uncommon to see all three types combined. Keeps are the first type. These consist of a masively thick wall of dry-fitted boulders or slabs of stone enclosing a small area. The interior is usually divided into a ramshackle arrangement of small chambers and halls piled on top of each other. Usually, there are no consistent floors but maybe the equivalent of three or four stories.
The second type is the hill fort. These are established by selecting a flat-topped hill and building a boundary wall of stones and timber around the crest. Within the enclosure there are huts, lean-tos, and one or two large halls.
The third type is a delving. It will consist of one or more entrances carved into a hollowed out hill. The interior is tunneled out to provide chambers and living space. Often, there will be watchtowers scattered about the summit which can only be entered via tunnels from below.
Any of these structures can be small only sheltering a small tribe of 30-50 or quite large with as many as 400-500 occupants. The size of the stronghold usually reflects the importance and power (or pettiness) of the local 'Goblin' King. Further North it is said there are very large strongholds incorporating keeps, atop delvings, within hill forts. Sometimes these places are commanded by a single Greater King or they might be home to rival, but lesser, Kings.