Formerly the family seat for the Quincarnon family, one of the mageblooded lineages of the Principalities of Glantri. Castle Blackhill crouches atop a rugged hill in Blackhill province. It is a low, sprawling structure of many wings and towers. The central keep is in good repair, but the outlying structures are disused, having been abandoned many years ago or damaged in the civil war.
When the Darokin legions seized Castle Blackhill, they cleared the fortress for their own use; the place remains in their hands, as a border fort for the occupying forces. But rather than investigating the chambers beneath the castle, they sealed them off so as not to deal with whatever dwelt below. The Quincarnons were known for their experimentations with living creatures, and their miscegenated creations — such as owlbears, or even the dreaded chimera — continue to haunt the Blackhill wilderness.
It is rumored that a secret entrance into the castle dungeons exists in the vicinity; certainly, a network of caverns winds beneath the highlands, and adventurers have often gone into those catacombs. While some have fought kobolds and other subterranean creatures, none have claimed to have found the Quincarnon family treasures.