From A Wiki of Ice and Fire
Cairns is a village in the Riverlands. It is disputed land between House Bracken and House Blackwood. It is currently held by House Blackwood.
A Dance with Dragons
Lord Jonos Bracken unsuccessfully asks Ser Jaime Lannister for Cairns for subduing Lord Tytos Blackwood. Tytos refuses to surrender it as part of the price to submit to the Iron Throne because his ancestors are buried there.
Behind the Scenes
Cairns are man-made pile of stones, historically used as burial monuments.
- ↑ A Dance with Dragons, Chapter 48, Jaime I.