Wyl is a castle in Dorne, the region of Westeros controlled by House Martell of Sunspear. The castle is located south-west of Storm's End and is the northern-most castle to hold fealty to Sunspear.
In the books
In the A Song of Ice and Fire novels, Wyl is the seat of House Wyl. It is located near the northern end of the Boneway.
Wyl is also the name of a guard of House Stark as well as a castle.
- Wyl at A Wiki of Ice and Fire (spoilers from the books)