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.
Seat of the FitzGeralds of Imokilly from the late 12th century until their lands were confiscated after the 1583 Desmond Rebellion, the roughly rectangular castle features a five-storey square keep and later 17th-century chimney ranges added under Sir Walter Raleigh and Richard Boyle, 1st Earl of Cork.
Designed by William Robinson during the reign of Charles II, Charles Fort is one of the finest surviving examples of a 17th-century star fort in Europe, with five bastions guarding Kinsale Harbour.
Built as Kinsale's customs house around 1500 by Maurice FitzGerald, 9th Earl of Desmond, the castle later became a naval prison known as the 'French Prison' for the French and Spanish captives held there, 54 of whom died in an 1747 fire.
Built by the O'Sullivan Beare clan to command Berehaven harbour and control sea fisheries, Dunboy was the site of a brutal two-week siege in 1602 by English forces under Sir George Carew during the Nine Years' War, after which the 58 surviving defenders were executed.
Built around 1601 for MacDonogh MacCarthy, Lord of Duhallow, as a show of Gaelic wealth and power, the castle was left unfinished after English Privy Council intervention in 1618 — neighbouring settlers feared its scale and defensibility.
Built in the 1420s on a small peninsula jutting into Sheephaven Bay, Doe Castle was the seat of the MacSweeney clan (gallowglass mercenaries of Scottish origin) for almost two centuries.
A 15th-century rectangular keep built around 1474 by Red Hugh O'Donnell I, chieftain of the powerful O'Donnell clan, on the banks of the River Eske in the heart of Donegal town.
Built between 1867 and 1873 by land speculator Captain John George Adair — notorious for the brutal Derryveagh Evictions of 1861 — and designed by John Townsend Trench in the style of an early Irish tower house.
A ruined Anglo-Norman motte-and-bailey built in the 12th century by John de Courcy, with an 82-foot-high motte topped by a stone tower that was enlarged into a tower house in the 15th century; a kidney-shaped bailey lies to its south, once separated by a defensive ditch..
Built by John de Courcy near the start of the 13th century following his invasion of Ulster, Dundrum Castle stands atop a rocky hill commanding sweeping views over Dundrum Bay and the Mourne Mountains, and was constructed to control access into the Lecale district from the west and south..
Likely built by Hugh de Lacy alongside Carlingford Castle on the opposite shore, Greencastle guarded the narrow entry channel of Carlingford Lough and the ferry crossing between the two.
Note: despite its name, Hillsborough is a Georgian great house rather than a fortified castle.
A rectangular four-storey tower house in the historic port town of Ardglass, with two projecting turrets on its north side joined by a machicolation arch, built in the same defensive style pioneered at nearby Kilclief Castle.
Built between 1413 and 1441, reputedly by John Sely, Bishop of Down, Kilclief is the earliest datable tower house in County Down.
Believed to be one of the oldest continuously inhabited castles in Ireland, with sections dating to 1180, Killyleagh Castle was redesigned in the mid-19th century by architect Sir Charles Lanyon in the style of a Loire Valley château, giving it a fairy-tale turreted silhouette overlooking Strangford Lough..
A well-preserved 16th-century tower house and bawn built by the Magennis family beside the Clanrye (Newry) River near Warrenpoint, replacing an earlier 13th-century Norman keep on the same strategically important site controlling the entrance to Carlingford Lough.
Founded between 1169 and 1216 by the Norman knight Hugh de Bernival (Barnewall), it is the only castle in Ireland still surrounded by a working flooded moat.
Built from 1204 on the orders of King John on the site of a Viking settlement, it served as the seat of English and British rule in Ireland for over 700 years.
Home to the Talbot family for almost 800 years (1185-1976), it is one of Ireland's oldest castles and set in a 260-acre demesne.
Built in 1583 by Adam Loftus, Archbishop of Dublin, it combines a defensible Elizabethan corner-towered house with lavish 18th-century Georgian interiors by James 'Athenian' Stuart.
Built around 1200 as a manorial residence for the Archbishops of Dublin, it is one of the earliest and largest Anglo-Norman castles in the country, enclosing over an acre within its walls.
Note: despite the name, Castle Coole is a late-18th-century Neoclassical mansion, not a fortified castle — one of the finest such houses in Ireland or Britain, seat of the Earls of Belmore near Enniskillen.