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 Tarlys are marcher lords of the Dornish Marches.
There is a pond that lies below the castle. Given the Tarly huntsman sigil and Lord Randyll Tarly's threats to kill Samwell Tarly while hunting, it may be surmised that the woods around Horn Hill are teeming with game.
According to legend, the castle was built on Horn Hill by the brothers Harlon the Hunter and Herndon of the Horn. Prior to the acquisition of the western marches by the Kings of the Reach, the castle was in a kingdom which extended from Horn Hill to Nightsong.
Two warlocks from Qarth sacrificed a bull aurochs at Horn Hill and had young Samwell Tarly bathe in its blood. When the act did not make his son stronger, Lord Randyll Tarly had the warlocks scourged.
A Clash of Kings
A Feast for Crows
Jon: Do you dream of Horn Hill?
Samwell: No. I hated it there.
- A Feast for Crows, Chapter 45, Samwell V.
- The Lands of Ice and Fire, Westeros.
- The World of Ice & Fire, The Targaryen Kings: Aenys I.
- A Feast for Crows, Chapter 15, Samwell II.
- The World of Ice & Fire, The Reach: Garth Greenhand.
- The World of Ice & Fire, The Reach.
- Fire & Blood, Three Heads Had the Dragon - Governance Under King Aegon I.
- Fire & Blood, The Sons of the Dragon.
- Fire & Blood, Birth, Death, and Betrayal Under King Jaehaerys I.
- A Game of Thrones, Chapter 26, Jon IV.
- A Clash of Kings, Chapter 31, Catelyn III.