In the land of Aviontix there are ruins. A lot of ruins. There are many sand buried cities, king’s tombs (They were a very religious people, focused upon their leaving to the afterlife), and huge statuary. However, Aviontix was a kingdom so long ago, that everything has been looted. (Figure there has been a whole historical epoch or two since then) There might be a hidden tomb or something somewhere in the lands, but it is unlikely. This does not stop people from selling maps to them all the time.
A massive iron key - 2’ length, 20 lbs forged with demonic faces from the bones and horns of demon-lords. When used with a massive portal - carefully built according to documents found in powerful books of evil knowledge, it will open into the realm of demons and allow them to flood into the world. The applications of this item for villains are obvious. Mortals touching this item are subject to [Effects_of_Touching_Powerful_Evil_Artifacts]