O'Brien's Castle
Description
O'Brien's Castle is an early 15th century tower house on Inisheer island, Ireland. A ringfort once stood on the site, named Dún Formna and dated to between the 5th century BC and 1st century AD.
The castle was built by the Clann Teige, a branch of the powerful O'Brien (Uí Briain) family, in the early 15th century around 1400. It was taken by the Ó Flaithbheartaigh (O'Flahertys) around 1582. It was captured and slighted by Oliver Cromwell's army in 1652, during the Cromwellian conquest of Ireland.
The castle is a rectangular donjon (keep). The original doorway was into the first floor, accessed by an external wooden stairs.
The entire first floor was a great hall, with mural stairs up to the parapet. The ground floor was a basement or storage area with three vaulted chambers. The corbel of a bartizan is visible with a human face carved into it.