History, why it matters, and the nearest castle hotel to base yourself in — for every notable castle in Ireland. Every recorded site, famous or obscure, has its own page too — browse by county below.
Built in 1625 by James Shaw, a Scotsman who settled on the Antrim coast in 1605, Ballygally is built in the style of a French chateau with a steep roof and corner turrets and remains one of the best-preserved 17th-century buildings still in daily use in Northern Ireland, today as a hotel with a reputed resident ghost, 'Lady Isabella'..
Built in 1177 by John de Courcy as his headquarters after conquering eastern Ulster, this is one of the best-preserved medieval structures in Ireland, with three-quarters of its perimeter surrounded by water on Belfast Lough.
A spectacular ruined castle perched on a basalt sea-stack on the Antrim coast, built in the 13th century by Richard Óg de Burgh, 2nd Earl of Ulster, later the seat of Clan MacDonnell.
Built in 1618 by Sir Faithful Fortescue, Constable of Carrickfergus Castle, who acquired the estate after tricking Gaelic chieftain Rory Óg MacQuillan out of his lands, Galgorm is regarded as one of the finest examples of Jacobean architecture in Ireland.
Built in 1636 by Sir Randal MacDonnell, 1st Earl of Antrim, Glenarm has been the family seat of the McDonnells, Earls of Antrim, for roughly 400 years and remains a working farm estate at the heart of the Glens of Antrim.
The four-storey ruins standing on Curran Point south of Larne Harbour, possibly built on the site of an earlier towerhouse of the Scoto-Irish Bissett family of Glenarm around 1250, though the surviving remains are thought to date from a 16th-century structure known as Curran Castle.
Note: a 19th-century country house rather than a true medieval fortification.
A small three-storey tower built in June 1601 by Lord Mountjoy to secure the strategically vital Moyry Pass and the 'Gap of the North' during the closing stages of the Nine Years' War, set within a small defensive bawn near the Armagh/Down border..
Originally the stronghold of the Gaelic O'Hanlon clan, the castle became the property of Sir Oliver St John, Lord Deputy of Ireland, during the Plantation of Ulster, and was ruined during the 1641 Irish Rebellion.
A National Monument about 3km east of Muine Bheag (Bagenalstown), Ballymoon Castle is a substantial 13th-century square courtyard castle unusual for having no keep, with four corner towers and mural chambers built entirely from local granite.
Built between 1207 and 1213 by William Marshal, Earl of Pembroke, on the banks of the River Barrow, Carlow Castle was once among the finest Norman fortresses in Ireland.
A 13th-century Anglo-Norman castle in the village of Clonmore, built on a roughly square plan with rectangular corner towers around a courtyard.
Built in 1625 by Sir Laurence Esmonde on the site of an earlier Norman fort in the village of Clonegal, Huntington Castle has been the seat of the Durdin-Robertson family since the 18th century.
A 19th-century Neo-Norman and Gothic-style castle near Kingscourt, built for the Foster family and later home to the Pratt family, set within 100 acres of parkland.
A rare Irish example of a circular lake castle, built on a small artificial island in Lough Oughter by William Gorm de Lacy, later held by the Gaelic O'Rourke and O'Reilly clans.
The present castle, likely built by the MacNamaras and completed around 1450, became the chief seat of the O'Brien clan from around 1500.
A distinctive circular tower house built from sandstone rather than the usual regional limestone, Doonagore overlooks Doolin and the Atlantic.
Set within Dromore Wood Nature Reserve near Ruan, this O'Brien tower house was repaired and expanded in the 1600s by Teige O'Brien.
Built in 1467 by Seán Mac Conmara, Knappogue became the seat of the MacNamara sept and, remarkably, remained continuously inhabited or maintained for over five centuries.
Built by the O'Brien clan on the edge of the Burren, the five-storey tower house was extended around 1648 by the formidable Máire Rua O'Brien and her husband Conor, who added a fortified manor house.
Built around 1550 for the O'Brien clan, Newtown is architecturally unusual: a cylindrical tower rising from a square pyramidal base, a design shared by only around 30 of Ireland's roughly 3,000 tower houses.
Seat of the powerful Barry family from the 12th century, the castle was deliberately damaged by its own occupants in 1581 to prevent English capture during the Desmond Rebellions, then repaired with new bawn defences.
Originally built to repel pirates and protect shipping approaching Cork Harbour, the castle was rebuilt in its current castellated form in 1829 after a fire.
Built in 1446 by the MacCarthy of Muskerry dynasty on the site of an earlier c.1210 stone fortress, Blarney is one of Ireland's most visited medieval keeps.
All 4,802 recorded castle sites across Ireland's 32 counties — ruins, tower houses and earthworks alongside the famous names.