Legends amongst treasure hunters and delvers that have been circulating for at least 300 years tell of a cave system deep in the treacherous jagged mountains in Mulle. A dragon hoard, of all things! The most unusual thing about this horde though is that the immesurable draconic wealth is practically out in the open, just inside one of the obvious cave entrances.

All those centuries ago when adventurers came in regularly to scope out this fabulous location and maybe lift some of it for themselves, no stories of triumph or dragonslaying came back with them. In fact, none came back at all. The location is cursed, any old maps that date back from those days have since been lost or destroyed.

The seasoned veterans of the trade of hoardstealing don’t go there now, and warn any would-be fortune seekers to do the same. Visitors to that remote place are so few and far between but every so often there’s someone too curious, too stubborn and foolhardy to listen to reason and they meet their fate there, to what exactly no one knows.

Not a single coin has ever been displaced from that cavern.

Asked for Smaugust prompts on Twitter and interpreted one as this, a dragon not only merged with his hoard but the caverns surrounding it. Ended up going further with it and turning it into a worldbuilding story.