White Harbor is the Manderly seat central to book politics but never shown as a major location in Game of Thrones.
Located at the mouth of the White Knife, White Harbor is the largest city north of the Neck and the North’s principal port. House Manderly rules it from the New Castle. Unlike many northern lords, the Manderlys descend from a house driven out of the Reach, which helps explain the city’s stronger southern, knightly, and mercantile influences.
White Harbor becomes crucial after the Red Wedding. Lord Wyman Manderly must publicly appear loyal to the Lannister-Bolton order while secretly grieving his son Wendel and maneuvering to restore Stark power. Davos Seaworth is sent there to win Manderly support for Stannis, leading to one of the novels’ most important northern political exchanges.
The show includes Wyman Manderly, but it does not take viewers to White Harbor as a substantial setting. The Eyrie is House Arryn’s mountain seat, Pyke is the Greyjoy stronghold, and Castle Black is a Night’s Watch fortress; none is the Manderly capital.