Located on a half acre island on Lough Corrib, Castlekirk, or Hen’s Castle as it is otherwise known, was an early 12th century tower house built by the sons of Ruaidrí na Saide Buide and aided by William FitzAldelm.
It is believed to be one of the oldest mortared castles in Ireland. In 1225, Odo O’Flaherty was forced to give the castle to Aedh Ua Conchobair, the king of Connacht, by the Lord Justice Sir Edmond Butler. In 1233, the castle was knocked down and rebuilt by Fedlimid, son of Cathal Crobhdearg Ua Conchobair in 1233.
Stories told outline that the castle got the name, ‘Hen’s Castle’ from the notable Gráinne Ní Mháille in 1546. Gráinne married Dónal an-Chogaidh O’Flaherty at the age of 16, who had the nickname ‘the Cock’ due to his aggressive nature, and as a result Gráinne was in turn called ‘the Hen’. However when her husband Donal was murdered, Gráinne fought back with fury and took the castle, where from that the castle became known as Hen’s Castle.
Other legends told say that the castle was built by a cock and a hen under the magic of a witch, hired by the O’Flaherty family.
The castle was occupied as a castle until Cromwellian soldiers took over in 1654. The castle fell into ruin and in later in the 19th century the ruin became further vandalised with its stones being removed to build houses in the area.