King John's Castle is located on the southern shores of Carlingford Lough.
The original castle consisted of an enclosed courtyard with two rectangular towers at the entrance and two-storey buildings within. The eastern half of the castle was added in 1261 ad and included a number of rooms and probably a great hall. There were a number of alterations made to the castle over the centuries.
Carlingford Castle appears to have remained in English hands during the post-mediaeval period. Hugh O'Neill, Earl of Tyrone, tried to take the castle in a surprise attack in 1596. The castle changed hands several times over the following centuries and was fired upon by retreating Jacobite forces in 1689. It also functioned as a hospital during the period leading up to the Battle of the Boyne.
View the Carlingford Pages on the Irish Walled Towns Network website.