This is my idea of what a drow outpost for raiding the surface might look like. Built into a cliffside, it has only one entrance to the surface, which is a narrow tunnel in the roof of a small cave, accessible only by a rope ladder, which would normally only be deployed when drow are coming or going.
The cottage above the cliff would have been built by the drow as well. Although they have no use for the building itself, they would need a way to vent the smoke from their cooking fire without drawing attention to the presence of their outpost. By running the house’s chimney directly to their vent shaft, they can make it look like the house is producing the smoke. Of course, this will not pass close inspection because the house itself has no fireplace or occupants. That might be useful as a way to allow the PCs in your game to discover the outpost.
Anyway, I hope you like it! I’m giving out the annotated version for free on this one: