Doga-Delloth is one of the vaults of Orv, the lowest level of the Darklands. It is located on the shore of the Sightless Sea, with the intellect devourer home of Ilvarandin to the north and the Black Desert to the east. Doga-Delloth is the home of the vile urdefhan race, although their settlements can also be found in the Midnight Mountains, on islands in the Sightless Sea, and in Ilvarandin.
The urdefhan have built a network of roads across the vault, linking together their cities and fortresses. Urdefhan settlements are most common on the coast of the Sightless Sea or near the primary tunnels leading in and out of the vault. In all, the urdefhan have eight major cities; Niovengia, the northernmost city on the Sightless Sea, is chief among them. Even though urdefhan settlements exist throughout the vault, and most of it can be considered "civilized", there are plenty of sparsely settled or "wild" sections as well.