Located in County Laois in the Irish Midlands, a low hill, the Rock of Dunamase, holds the ruins of the 12th century Dunamase Castle. An earlier fort, or dun, preceded it.
When Aiofe, daughter of Dermot MacMurrough, married Strongbow, the 2nd Earl of Pembroke, the castle passed into Anglo-Norman hands.
After Aiofe and Dermot's daughter Isabel married the Earl of Pembroke William Marshal, the castle became a military and administrative centre. It passed to the Mortimers in the 14th Century. When Earl of March Roger Mortimer was executed for treason, it changed hands again, then fell into disuse.
The 18th century saw a partial and temporary restoration when the hall became the residence of Sir John Parnell, Irish Parliamentarian and grandfather of Charles Stewart Parnell, the 19th century champion of Irish Home Rule.
As the OPW marker explains, this castle, on its small hill with a wide view in all directions, was well-fortified. Surrounded by a double barbican, it featured plunging arrow loops in the walls.