From A Wiki of Ice and Fire
Mermaid's Palace is a small isle off the coast of the Arbor.
A Feast for Crows
Mermaid's Palace is attacked and conquered by the ironborn, along with the Isle of Pigs and Stonecrab Cay. It is now used as one of their bases.
- ↑ 1.0 1.1 A Feast for Crows, Chapter 45, Samwell V.