Horn Hill is the seat of House Tarly in the Reach. Located on an eponymous hill, the castle lies south of Highgarden and a hundred leagues northeast of Oldtown among the thickly-wooded foothills of the Red Mountains. The Tarly's are marcher lords of the Dornish Marches.
There is a pond that lies below the castle. The woods around Horn Hill were once teeming with game, but over-hunting, the blight and winter has seen a drastic reduction in wildlife.
- Leonette Tarly, Dowager Lady of Horn Hill
- Bonifer Tarly, Lord of Horn Hill
- Franklyn, Steward of Horn Hill (deceased, killed during the Coup at Horn Hill)
- Lucifer, Spymaster of Horn Hill
- Ser Varus of the Channels, Captain of the Guard
- Tyro, Master-at-Arms
- Maester Theomore (deceased)
- Maester Erryk (deceased)
- Trystane, Cofferer of Horn Hill (deceased, killed during the Coup at Horn Hill)