Seagard

Seagard is a castle in Game of Thrones. It is the seat of House Mallister, a vassal house holding fealty to House Tully of Riverrun. The castle is located north of Riverrun, on the coast of Ironman's Bay. It lies between the red fork and the blue fork of the Trident. Seagard was built as a defense against marauders from the Iron Islands.

In the books
In the Song of Ice and Fire novels Seagard is the same.