1. The First Men
(World of Westeros/History)

... though, the children only forced future invaders to turn to sailing ships. The First Men spread throughout the continent, and even settled the Iron Islands. It was they who found the Seastone Chair standing ...

2. Pyke: An In-Depth Look
(News/Latest News)

Here's a more in depth look at Pyke, with toolset screen shots and in-game screen shots:

3. Pyke: A First Look
(News/Latest News)

Rising high above the stormy seas in the midst of Ironman’s Bay lies the island of Pyke, seat of House Greyjoy. From the Seastone Chair, Balon Greyjoy and his progeny rule the Ironborn and hatch nefarious ...

4. Lordsport
(World of Westeros/Cities)

... to wed Daenerys Targaryen, claim the Iron Throne, and give the Seastone Chair to his brother Victarion.  ...

5. Pyke
(World of Westeros/Strongholds)

...  The Great Keep The Hall of Greyjoys, or Great Keep, is a large keep with a long smoky central hall, capable of sitting 400 men. It also houses the Seastone Chair, the throne of the Iron Islands. The Seastone ...

6. The Iron Islands
(World of Westeros/Geography)

... the Greyjoys rule the Iron Islands from the kraken-shaped Seastone Chair in Pyke, and command one of the strongest navies in the Seven Kingdoms. Bastards born in the Iron Islands are given the surname ...

7. History
(Category)

... as well, such as those who left the Seastone Chair behind on the Iron Islands. Eventually, all would either disappear or fall to invaders from the east.  ...