I'm channeling some sort of mutant combination of Richard Corben and Vaughn Bodé today…
Out in the Aurora Badlands, beyond the safety of civilization, is a great pillar of igneous rock. Thrust high into the colorful sky, this place is known only as The Tombs. It is an ancient burial site, abandoned for millennia. Riddled with twisty catacombs and secret burial vaults, the Tombs are said to be the province of the undead. Sane men won't set foot anywhere near the place.
The Tombs are said to glow with a spectral light in the dark hours. It is unknown whether this is due to the unhallowed nature of the place or some weird source of radiation. In any case, The Tombs are located in the middle of radioactive badlands. Caution must be exercised in the approach, for in addition to radiation and inclement weather, this region is beset by countless irradiated horrors.
Dungeon Masters take note: this place is one of those sprawling dungeon complexes you often read about. It has been carved out, layer upon layer, over long ages. Its network of charnel vaults and catacombs, constructed without rhyme or reason, twists deep into the pillar of rock.
This is but one "level" of The Tombs. Hundreds of similar areas are situated throughout the pillar. This particular area is accessible only by a series of portals located on a ledge 730 feet above the ground on the pillar's southern face. There are no doors in this place, although some ways are blocked, either by bars or pits. Who or what is interned within is up to you. Whatever it is, I expect that it is grotesque in the extreme. GOOD LORD! *CHOKE*
The Fine Print: I am sharing this map under a Creative Commons Attribution-Noncommercial-Share Alike license. If you follow that link you will be able to read about the conditions that apply to this work. In a nutshell: (a) you can't use it commercially, (b) you must attribute it to me, and (c) you must share any derivative works that you create.