Carlow Castle, County Carlow

This great keep was formerly one of the most impressive Norman castles in Ireland. Only the western wall and two towers now survive, the remainder having been accident ally blown up in 1814 by "a ninny-pated physician of the name of Middleton" who leased the building for use as a lunatic asylum and "applied blasts of gunpowder for enlarging the windows and diminishing the walls, and brought down two-thirds of the pile into a rubbishy tumulus in memory of his surpassing presumption and folly".

The original keep was a three-storey rectangular block with cylindrical corner towers, probably built between 1207 and 1213 by William Marshall on the site of a motte erected by Hugh de Lacy in the 1180s. It may be the earliest example of a "four-towered" keep in the British Isles and appears to have been directly inspired by French examples, notably Nemours (Seine-et-Marne) built between 1160 and 1180. The entrance lies at first-floor level in the north wall and access to all storeys which had timber floors, was by way of stone stairways in the thickness of the west wall.

Ownership of the castle passed to the Crown in 1306 and was later granted to the Earls of Norfolk, who held it until confiscation in 1537. It was captured by James FitzGerald in 1494, again by Silken Thomas in 1535, and changed hands a number of times before being purchased by Donough, Earl of Thomond in 1616. It fell to the Confederates in 1642 but was later returned to Thomond after being liberated by Ireton in 1650.

Located in the town centre. Access is through Corcoran's Mineral Water factory.
NGR: S 718767 National Monument. Open weekdays only. The key can be obtained from the factory's office.