Grennan Castle
Built in the 13th century by Anglo-Norman lord Thomas FitzAnthony on the west bank of the River Nore at Thomastown, this rectangular castle remained in good condition until the early 19th century.
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 the 13th century by Anglo-Norman lord Thomas FitzAnthony on the west bank of the River Nore at Thomastown, this rectangular castle remained in good condition until the early 19th century.
Built in 1195 by William Marshal on the site of an earlier wooden fortification, Kilkenny Castle was the principal seat of the Butler family (Earls and later Dukes of Ormond) for almost 600 years.
Built by the Gaelic Mac Giolla Phádraig (FitzPatrick) chieftains of Upper Ossory, Ballaghmore is decorated with carved Sheela na gig figures on its walls, a rarity for a tower house of this scale.
Built in the 1260s by Maurice FitzGerald, 2nd Baron of Offaly, on the banks of the River Barrow near Portarlington, Lea Castle was later seized and held by the Gaelic O'Dempsey clan during the medieval Irish resurgence.
A rocky outcrop rising 46 metres above the surrounding plain, first a Gaelic ringfort recorded as sacked by Vikings in 843, then rebuilt as a stone castle after 1170 by Strongbow following his marriage to Aoife, daughter of the King of Leinster.
Standing on the historic grounds of the medieval Mac Raghnaill (Reynolds) clan estate on the shores of Lough Rynn, the current mock-Tudor revival house was built in 1833 by Robert Bermingham, Viscount Clements.
A restored 17th-century plantation manor house on the shores of Lough Gill, built by Captain Robert Parke in the 1630s on the site of an earlier O'Rourke tower house, using traditional Irish oak in its 20th-century restoration.
Set on the banks of the River Maigue in Ireland's self-styled 'prettiest village', Adare Castle passed through several owners before becoming significant to the Earls of Desmond in the 16th century.
Founded in 1199 by William de Burgo on a rock in the River Deel, Askeaton became the power base of the Earls of Desmond after 1348 and successfully resisted English attack in 1579.
Perched on a volcanic rock above the Shannon Estuary near Clarina, Carrigogunnell was described by Lord Deputy Leonard Grey in 1536 as 'the key of all the county'.
Built by the FitzGerald Earls of Desmond and fortified with curtain walls by 1298, the 15th-century great hall was used for banqueting and entertainment by the Desmond court.
Built in 1462 on a site occupied since AD 983, Glenquin passed from the O'Briens to the Geraldines during the Desmond Rebellions and was partly demolished on the orders of Sir Walter Raleigh.
Seat of the Knights of Glin, a FitzGerald branch dating to the 14th century, the original tower house was abandoned in the late 1600s.
Built on the orders of King John on King's Island beside the River Shannon, on a site previously settled by Vikings in 922, the castle withstood five sieges in the 17th century.
The ancestral seat of the O'Cahan clan, who ruled the area for centuries until Sir Donnell O'Cahan was implicated in treason in 1607 and fled during the Flight of the Earls.
Built around 1199 by Norman knight Richard de Tuite on top of an earlier ringfort, Granard Motte is, at 163 metres, the highest motte in Ireland and features an unusual double bailey reflecting its importance as a frontier fortress against the O'Reilly clan.
A tower house near Lanesborough on Lough Ree associated with the O'Farrell clan, dominant lords in medieval Longford, later dismantled by Cromwellian forces and further ruined during the Williamite wars.
Built in 1236 by Lady Rohesia de Verdun on a rocky outcrop northwest of Dundalk near the Northern Ireland border, its triangular plan follows the shape of the cliff edge, making it naturally defensible on two sides.
Built by Norman knight Hugh de Lacy in the late 12th century overlooking Carlingford Lough, the castle takes its name from King John of England, who is said to have stayed there for three days in 1210 during his Irish campaign.
A sturdy three-storey tower house in the coastal village of Termonfeckin, built with a vaulted second floor, spiral stairs and a distinctive projecting turret.
Founded in 1228 by the Anglo-Norman de Burgo (Burke) family on the shores of Lough Corrib, the estate passed to the Brownes and then, in 1852, to the Guinness family, who added the Victorian wing, turrets and terraced gardens that give Ashford its fairy-tale silhouette today.