Blackhaven is a castle in the Dornish Marches, in the southwestern Stormlands. It is the seat of House Dondarrion, a vassal house holding fealty to House Baratheon of Storm's End. The castle is located south-west of Storm's End near the border with Dorne.
In the books
In the A Song of Ice and Fire novels, Blackhaven is a stout keep that has a long history as a defensive fortification against attacks out of Dorne to the south. It has black basalt walls, dry moat that's said to be bottomless, and the castle is small and modest in comparison to the great castles of the Seven Kingdoms. According to legend, the castle was granted by the Storm King to a loyal scout who avoided Dornish patrols to bring him warning of an impending attack. At one point the scout was ambushed, but his attackers were killed in a freak lightning strike. As a result, the scout, who was the founder of House Dondarrion, adopted a lightning bolt as his symbol.
Blackhaven is the home of Lord Beric Dondarrion.