The Slayne is a river in the stormlands. Known for its rapids, pools, and waterfalls, the Slayne flows north to south in the northeastern Red Mountains, west of Cape Wrath. The castle of Stonehelm, the seat of House Swann, overlooks the Slayne, a major river route in the stormlands.
In the Battle by the Bloody Pool, King Durran the Young is said to have dammed the Slayne with Dornish corpses. During the Andal invasion, King Cleoden I Durrandon allied with three Dornish kings and defeated the Andal warlord Drox on the river.