Riverrun

"... when I first saw the stone walls of Riverrun rising from the Trident, towering over me, back then, I was a little more easily impressed. The boy in me thought the gods themselves must live in such a place. I soon learned otherwise."

- Petyr Baelish

Riverrun is the former seat of House Tully, which is now occupied by its new lawful rulers House Frey with support from the army of House Lannister. 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.

Background
Riverrun is the seat of House Tully, the Lord Paramounts of the Trident and the Riverlands. Prior to the War of the Five Kings, Lord Hoster Tully is the ruler of Riverrun.

Season 1
During the War of the Five Kings, a Lannister army under Ser Jaime Lannister lays siege to Riverrun. Northern forces under Robb Stark lure Jaime's men into a trap at the Battle of the Whispering Wood, breaking the siege of Riverrun.

Notable residents of the castle

 * Lord {Hoster Tully}, the late Lord of Riverrun and Lord Paramount of the Trident.
 * 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. Murdered by Lord Petyr Baelish.
 * Lord Edmure Tully, the last Tully Lord of Riverrun and Lord Paramount of the Trident. Now a hostage of the Iron Throne.
 * Ser {Brynden Tully}, known as "the Blackfish", Lord Hoster's brother. Killed by Lannister and Frey soldiers after Riverrun is retaken by the Iron Throne.

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.

Prior to the Red Wedding, Robb leaves Blackfish holding Riverrun as "Warden of the Southern Marches", overseeing the defenses of the Stark-loyal territories of the Riverlands, and protecting his Queen, Jeyne Westerling (the book's counterpart of Talisa Maegyr), who also remains at Riverrun.

Following the Red Wedding, according to the agreement between Tywin Lannister and the Freys, Riverrun is granted to Emmon Frey, the second son of Lord Frey and husband of Tywin's sister Genna. Ryman Frey leads two thousand spears to take Riverrun, reinforced by Lannister troops led by Ser Daven Lannister, the new Warden of the West, and several Riverlords that bent the knee following the Red Wedding. However, Brynden anticipates the siege. He gathers all the foodstuffs and goods he can within the castle, expels all the unnecessary mouths, and prepares for a long siege. Like in the show, Edmure accepts Jaime's terms and yields. Emmon Frey takes his place as Lord of Riverrun.