Stonehelm is a castle in the Stormlands and the seat of House Swann, a vassal house holding fealty to House Baratheon of Storm's End. The castle is located southwest of Storm's End on the northern shore of the Sea of Dorne.
In the books
In the A Song of Ice and Fire novels, Stonehelm is located at the mouth of a river, at the south end of Cape Wrath and east of the Dornish Marches. It was built to oversee a major river route inland to the Stormlands.