The Tower of Joy is a tower located on the northern edge of the Red Mountains of Dorne. This was the home of Prince Rhaegar Targaryen and Lyanna Stark after they eloped and married in secret. It also is the birthplace of Jon Snow (whose real name is Aegon Targaryen).
During a Greenseer vision under the guidance of the Three-Eyed Raven, Bran Stark and his mentor witness the confrontation between Ned Stark and five of his bannermen against Ser Arthur Dayne and Ser Gerold Hightower, the last members of the Kingsguard still loyal to the late King Aerys II Targaryen. The fight ends with the deaths of all swordsmen save for Ned Stark and Howland Reed. Ned then enters the Tower after hearing a woman's scream from inside.
Some time later, Bran enters another vision by communing with a Weirwood tree in the Haunted Forest. This time, Bran follows his father into the Tower of Joy, and witnesses the reunion of his father with a dying Lyanna Stark, who entrusts Ned with the protection of her newborn son, a baby who will grow up as Jon Snow.
In the books
In the A Song of Ice and Fire novels, the Tower of Joy is located in the Red Mountains of Dorne. It lays in the Prince's Pass, with the Nightsong to the north and Kingsgrave to the south. This tower was named the "Tower of Joy" by Prince Rhaegar Targaryen.
Ned accompanied six men to the tower in order to retrieve his sister. The six accompanying him were:
- Howland Reed
- Willam Dustin, husband of Lady Barbrey Dustin and the head of House Dustin
- Ethan Glover, former squire to the late Brandon Stark (son of Rickard)
- Martyn Cassel, father of Jory Cassel and brother of Rodrik Cassel
- Theo Wull, of Clan Wull
- Ser Mark Ryswell
When he is injured in a fight with Jaime Lannister in King's Landing, Ned dreams of the fight. He recalls seeing the Kingsguard in their white cloaks. After a battle with the Kingsguard, which only Ned and Howland Reed survived, Ned heard his sister's screams coming from the tower. When he finds her, she is in a bed of blood. He makes an unknown promise to her before she dies. The words "Promise me." haunt Ned for the remainder of his life.