The Dank Dungeons of Dannak
The Rûgari were the people of an empire that controlled the lands hereabouts for many hundreds of years. Sometimes ruled by benevolence, sometimes cruelty, they always saw themselves as superior to all others in their realm. Toward the end of their reign, true megalomania overtook the emperors. They became convinced they were gods, and that the Rugar in general were near-celestial beings.
Their great city sprawled across a lush valley, cradled between two arms of the Starspur Mountains. The city, originally walled, grew far beyond its modest beginnings. Eventually, all thoughts of walling the city were abandoned. Instead the valley mouth was walled, and the inhabitants of the great city had the length and breadth of the valley to call home. Watch towers were constructed along the spurs to guard those passes down into the valley. At the head of the valley the mighty fortress of Dannak was erected. It crouched over the headwaters of the Velspé River, carved from the very slopes of Mt. Kander.
Beneath the great fortress were built countless miles of tunnels, chambers, libraries, temples, and all manner of things. The emporers saw Dannak as their final bastion should calamity befall their empire, and provisioned it thus. Being haughty and wasteful, no emporer would demean himself by occupying a predecessor's lodgings in Dannak. Each emporer had his own domocile carved from the rock. Some ordered previous quarters sealed, either walled up or buried beneath controlled cave-ins. Eventually it became impossible to accurately determine the extent of the dungeons.
Then, in a night, the empire was gone. The cause remains unknown, and perhaps unknowable. All that is known comes down from citizens whose dwellings were near the wall at the mouth of the great valley. They reported seeing a rolling, boiling mist issuing from Dannak. It moved down the valley with unnatural speed and purpose. There were disembodied voices in the mist, laughing and cavorting. Every living person touched by the mist died, screaming and choking, within seconds. Crops and livestock, too, were killed, but not wild things still growing and making their lives in the valley.
Thus it was, that in the span of a single night, the mighty Rûgari Empire was brought low. Their great city became a graveyard, and their mighty fortress became a tomb, cursed and haunted.