The causeway is a raised log-and-plank road, crooked and rotting. East of the road is a bleak and barren shore and the cold salt sea of the Bite, while to the west are the swamps and bogs of the Neck, impassible and deadly. At the northern end of the causeway, the three remaining towers of Moat Cailin are positioned so that any enemy coming up from the south must pass beneath and between them. Even a small garrison at the Moat can play havoc with any army coming up the causeway.
A Game of Thrones
A Clash of Kings
While Robb is fighting in southern Westeros during the War of the Five Kings, Lord Balon Greyjoy sends his brother Victarion with the Iron Fleet to capture Moat Cailin and block Robb from retreating on the causeway.
A Storm of Swords
House Frey abandons Robb's cause after he weds Jeyne Westerling instead of a daughter of Lord Walder Frey. Robb fears that if he marches north on the causeway, he will be caught between Freys and Victarion's ironborn.
For his planned siege of Moat Cailin, Robb intends to have Lord Bolton and the Greatjon lead two hosts up the causeway. Meanwhile, Robb would lead a third northern host through the swamps of the Neck with the aid of the crannogmen, and then reappear north of the Moat to surpise the ironborn. Robb is betrayed in the Red Wedding and killed at the Twins before he can put his plan into effect, however.
A Dance with Dragons
Lord Bolton leads an army of mostly Freys and Boltons north on the causeway toward Moat Cailin. After Theon Greyjoy negotiates the surrender of the ruined castle, Ramsay Bolton has the ironborn garrison flayed and their corpses displayed along the causeway. Ramsay sends riders south on the causeway to inform his father that it is safe to reach Moat Cailin.
They had been twelve days crossing the Neck, rumbling down a crooked causeway through an endless black bog, and she had hated every moment of it. The air had been damp and clammy, the causeway so narrow they could not even make proper camp at night, they had to stop right on the kingsroad.—thoughts of Sansa Stark
—thoughts of Theon Greyjoy
- A Game of Thrones, Chapter 15, Sansa I.
- A Dance with Dragons, Chapter 20, Reek II.
- A Game of Thrones, Chapter 55, Catelyn VIII.
- A Game of Thrones, Chapter 56, Tyrion VII.
- A Game of Thrones, Chapter 59, Catelyn IX.
- A Game of Thrones, Chapter 71, Catelyn XI.
- A Clash of Kings, Chapter 24, Theon II.
- A Storm of Swords, Chapter 14, Catelyn II.
- A Storm of Swords, Chapter 45, Catelyn V.
- A Storm of Swords, Chapter 51, Catelyn VII.