The Darklands
The Darklands are an immense series of caverns, vaults, and passages under the surface. While entrances to the Darklands can be found throughout the world, it is not common for travelers to venture into the almost universally unsafe depths, making the subterranean realm almost a world unto itself.
Geography
The Darklands can be divided into two known distinct layers, each with their own characteristics, inhabitants and hazards. The Darklands has been noted do be divided into separate cave systems these caves run under most if not all of the land area of Europe.
Nar-Voth
Nar-Voth is the uppermost of the three regions—the "wilderness" of the Darklands. Most explorers of the Darklands are only familiar with this region. It is mostly composed of a series of cave networks connected by lengthy twisting tunnels. For a cave network to be considered part of this region, there must be a connection to the region of Sekamina below. Nar-Voth's cavern systems do not form a continuous network, and travel between them often requires passing through Sekamina or over the surface.Sekamina
Below Nar-Voth lies the largest realm—Sekamina. This region consists of a vast underground warren of tunnels that span continents. Found here are also great underground rivers and lakes. Most of the entrances to Sekamina require traveling through Nar-Voth first, but it is believed there are exceptions.Fauna & Flora
The Darklands play host to as wide an array of creatures as the surface world. Some are intelligent and civilized, while others are bestial, savage, and primal. Throughout the three layers that make up the subterranean domain, one can find any number of settlements which rival their above-ground counterparts.
The 'civilized' races that inhabit the upper layer include Drow, Oread, Ratfolk, Changelings, Astomoi, Duergar, Svirfneblin, and Driders. Most of these races are relatively isolated, tribal, or small, with the exception of the duergar, who occupy a number of abandoned pre-existing dwarf cities.
Hazards
The Darklands are a dangerous place, a fact to which anyone who has ever journeyed there can easily attest. This is partially due to the fact that compared with the surface world, food sources are extremely scarce there. This makes the competition for those sources that do exist that much more intense. Perhaps because of this, the creatures and inhabitants of the Darklands, all up and down the food chain, are quite deadly. In addition to the obvious threats presented by deadly predators, insatiable scavengers, and diabolical ambushers, there are the more mundane, but nevertheless lethal, hazards of the Darklands. Air Most of the air found below is safe to breathe, if a little stale. In areas blocked off by tunnel collapses or water, or near sources of noxious gases, however, it can become dangerous to travellers. The air near large magma flows can be quite caustic, and poisonous gases like carbauxine or quickdeath can lead to an even quicker demise. Fungi, slimes, and molds Most plants have little chance of surviving in the dry, dark caverns of the Darklands. There is simply not enough water or light (with the exception of some of the stranger Orvian Vaults) for them to live. Instead, those who live here largely rely on the various fungi, molds, and slimes for sustenance. But like everything else in this hostile environment, these plants can be dangerous as well. Among the fungi, these include the rot-inducing violet fungus, the animating slaver fungus, the brain-damaging cytillesh, and twilight mushrooms. The dangerous molds include the cold-exuding brown mold, russet mold which gives birth to vegepygmies, poisonous yellow mold, and life-draining ghost mold. Harmful slimes of note include the corrosive green slime and the innocuous-seeming olive slime. Creatures The Darklands are home to many strange creatures, including the stirge hound, ether frog and ghost bat.
Races found here
Drow
Oread
Ratfolk
Changelings
Astomoi
Duergar
Svirfneblin
Driders
Drow
Oread
Ratfolk
Changelings
Astomoi
Duergar
Svirfneblin
Driders