Gods Eye

Gods Eye is an immense lake, the largest inland body of water in Westeros. It is located north-west of the Crownlands, south of the Riverlands, north of the Reach and not far east of the Westerlands. Small fishing villages dot its shores, but the most significant settlement is the ill-omened castle of Harrenhal, located on the north shore.

In the books
In the Song of Ice and Fire novels, the Isle of Faces is reputed to be located in the centre of Gods Eye, the home of 'greenseers' who keep the traditions and secrets of the long-vanished Children of the Forest. The island is said to be home to many weirwood trees. The Isle has a fell reputation and most avoid it.

Gods Eye feeds a river which is a tributary of the Blackwater Rush, but does not appear to be navigable by large ships.