The Graycliffs

The Graycliffs are the uppermost region of the Sunken Lands, and the only region where permanent settlements have been made that do not completely give in too madness. Throughout the Graycliffs can be found sizable enclaves of Drow, Duergar, and other races that have adapted to the unforgiving landscape and limited light. The corrupting influence has only a limited effect on the inhabitants. They do not typically fall to madness, but it does tend to result in most individuals being more self centered, and less willing to help others, especially when surviving is already a struggle. Many natives of the Graycliffs hold some amount of resentment or at least suspicion when it comes to outsiders, and the fact that some surface nations also choose to exile criminals to the Sunken Lands further adds to their suspicion.

The Graycliffs are divided into two main continents, separated by the Sea of Shadows. The Northern Graycliffs are colder, and more barren, but are more populated as the Southern Graycliffs contain far more entrances to the Deeptrenches, and are commonly invaded by the creatures that live deeper underground. Much of the Graycliffs are, as the name implies, barren cliffs, but there are a variety of biomes hidden between the different crags and mountains. Proper farmland is rare, and generally hotly contest over by the various groups in the area.
Heating is also a common issue throughout the Graycliffs. The lack of sunlight and low amounts of wood for fire means that natural thermal vents are important for warmth. Many settlements are built around these vents, and keep track of additional vents nearby, in case they need to relocate. Expanding these vents and taping into them it properly heat multiple homes is a dangerous job, as a sudden blast of scalding hot air or poisonous gas is an ever present risk.
The Graycliffs only contain a few permanent settlements as there are a variety of reasons a village would need to relocate. Seismic activity changing access to resources, the end of a central heating vent that provided warmth, or a dangerous monster moving into the area are only a few examples. Most villages end up being at least semi nomadic, building a settlement in a stable spot for a few years, then moving when they have to. The constant movement has also made trade a rather complex affair. Individual villages will develop a special code called a Waysign they will teach to trusted merchants, to allow them to follow whatever trail the village leaves if they have to move suddenly. This makes it so that trusted individuals can maintain trade and communication between villages, but they can still remain hidden from the less savory individuals, who might see a village as a good target for raiding. Each village has their own unique Waysign, that is known by the villages, but only to a few other trusted people. Revealing the Waysigns to someone who has not been granted permission by the village is considered a grave betrayal as it risks the safety of the entire village.
There are only a few large permanent cities that can be found throughout the Graycliffs. These are Eml Dorei, the capital of the drow, Durn Faldhr, the fortress of the Duergar, and Blackhaven, a city built by exiles from the surface and their descendants.