Riverrun

Riverrun  is the former seat of House Tully, who continue to hold it in defiance of the Iron Throne and its new lawful rulers, House Frey. It is a large castle located in the central-western part of the Riverlands. It sits at the point where the Red Fork of the Trident River is joined by its major tributary, the Tumblestone River flowing out of the west. In times of danger, sluice gates can be opened to flood a channel cut to the west of the castle, turning Riverrun into an island. Its walls rise sheer from the waters and its towers command the opposite shores, making assaulting it almost impossible without huge casualties.

Notable residents of the castle

 * Lord {Hoster Tully}, the late Lord of Riverrun and Lord Paramount of the Riverlands.
 * Lady {Minisa Whent}, his wife, who died many years ago in childbirth.
 * Lady {Catelyn Tully}, his eldest daughter, widow of Lord Eddard Stark. Catelyn was, along with her son Robb Stark and many other North men, slain at The Twins during the wedding ceremony of her brother Edmure to Roslin Frey.
 * Lady Lysa Tully, his second daughter, widow of Lord Jon Arryn and Lady Regent of the Vale. Currently at the Eyrie.
 * Lord Edmure Tully, the last Tully Lord of Riverrun and Lord Paramount of the Riverlands. Now a hostage of House Frey.
 * Ser Brynden Tully, known as "the Blackfish", Lord Hoster's brother.

Behind the scenes
The grounds of Gosford Castle in County Armagh, Northern Ireland were used for Riverrun exteriors during Season 3.

The design was loosely based on Château de Chenonceau.

In the books
In the A Song of Ice and Fire novels, Riverrun is a triangular castle made of sandstone. It is located at the confluence of the Tumblestone River and the Red Fork of the The Trident River.

Riverrun has been in the possession of House Tully for a thousand years. It became the seat of rule over the region when House Tully rebelled against the ironborn occupiers and allied with Aegon the Conqueror three centuries ago.