169 Old Ruins to Explore in Leinster

Clonmacnoise is a ruined monastery situated in County Offaly in Ireland on the River Shannon south of Athlone, founded in 544 by Saint Ciarán, a young man from Rathcroghan, County Roscommon. The wooden castle that stood on the top of the motte at Clonmacnoise was destroyed by fire and later in 1214 the Justiciar of Ireland, Henry of London, built a stone castle on the motte.

Clonmore Castle is a 13th century Anglo-Norman castle located in Clonmore, County Carlow, Ireland. The castle is roughly square in plan with rectangular towers at the southern sides of the courtyard. Due to a lack of heritage preservation, most of the castle is now covered in ivy, and large gaps have appeared in the north and west walls. The building is now entirely empty with no trace of a stone floor.

Dún Dealgan Motte is a motte and National Monument in Dundalk, Ireland. Some legends claim the site as the birthplace of Cú Chulainn, and it is here that he bases himself in the Táin Bó Cúailgne. The Annals of the Four Masters places a battle here in 500 AD. The house was rebuilt in 1850 by Thomas Vesey Dawson as a country retreat, but fell into disrepair and was bought by the County Louth Archaeological and Historical Society to be used for a museum.

Cullahill Castle was the principal stronghold of the MacGillapatricks of Upper Ossory built around 1425 and destroyed around 1650. Cullahill Castle takes its name from an ancient forest that covered Cullahill Mountain and extended down to Cullahill village. It was constructed around 1425 by the MacGillapatricks of Upper Ossory, Finghin MacGillapatrick being the possible builder.

Dangan Castle is a former stately home in County Meath, Ireland, which is now in a state of ruin. It was the childhood home of Field Marshal Arthur Wellesley, 1st Duke of Wellington. The modern house was originally built in the early 1700s as Dangan House by Richard Colley, who demolished the old castle. Colley had inherited the estate from the childless Gerald Wesley, on condition that he changed his surname.

Delvin Castle was built in 1310 by Sir Gilbert de Nugenton who was brother-in-law to Hugh de Lacy, Lord of Meath.The castle originally consisted of a central rectangular block with a five storey circular tower on each corner. Only half of the structure remains today as the north east section (including towers) was demolished many years ago. A private house and a shop now occupy the northern section of the site.

The first Manor house was built by the Normans in the 12th Century and many castles were built on the site throughout the Middle Ages. The castle was extensively damaged in the 1641 rebellion, then rebuilt in 1773, and gothicised in 1827 by the architect Sir Richard Morrison. By the mid 1800s the Donadea estates were one of the largest in Co. Kildare, amounting to almost 16,000 acres.

The Donaghmore Round Tower is a well-preserved 10th-century construction situated just northeast of Navan in County Meath. The architectural style of the church indicates it was built in the 15th Century. Most likely, it replaced an older church built in the Romanesque style; a carved Romanesque head is incorporated in the south wall of the bell tower. At the site, visitors can view the remains of a church and the round tower, which has interesting carvings and sculptures.

Donore Castle is a tower house and National Monument in County Meath, Ireland. The castle has three storeys, and measures 7.3 × 6.3 m at the base, and is 12 m (39 ft) tall with rounded corners a projecting round tower at the corner housing a newel stairway. One of the Castle's defenses is a murder hole situated at roof level above the entrance door. There are also carved heads of a king and bishop above the doorway.

A 5,500-year-old passage tomb uncovered at Dowth Hall in the heart of the Brú na Bóinne World Heritage site in Co Meath is “the most significant megalithic find in Ireland in the last 50 years”, archaeologists believe. It is less developed as a tourist attraction than its neighbours, partly because the chamber is much lower, and partly because the decoration is less visible.

Duckett's Grove was originally a three-storey over basement Georgian country house built circa 1745.The interior of the house was destroyed by a major fire in the 1930s and is now inaccessible. Even in ruin, the surviving towers and turrets of Duckett’s Grove Walled Gardens and Pleasure Grounds form a romantic profile making it one of the most photogenic historic buildings in the country and a castle in Ireland to visit.

The Dun Ailinne site is a large circular enclosure located on the hill of Knockaulin in County Kildare Ireland. Documentary sources traditionally refer to it as one of four Irish ‘royal’ sites–significant pre-Christian social and political centers. Excavations in the 1960s indicated that the site was an important center of ceremonial and ritual activity during the Irish Iron Age.

Dunbrody Abbey is a former Cistercian monastery in County Wexford, Ireland. The cross-shaped church was built in the 13th century, and the tower was added in the 15th century. With a length of 59m the church is one of the longest in Ireland. The visitor centre is run by the current Marquess of Donegall and has one of only two full sized hedge mazes in Ireland.

Dunmoe Castle is a castle and National Monument located near Navan, Ireland. The Castle was built in the 15th Century and was home to the D'arcy family. The Castle, originally a four turreted structure, is now, through years of ruin, reduced to just two. It remained intact until it was destroyed by fire during the 1798 rebellion and today visitors can see what remains of the four-storey castle. It can be found between Navan and Slane.

Dunsany Castle is situated on an estate that comprises of marsh, wood and farmland with the River Boyne running along the back of the land. It is located in the village of Dunshaughlin, 6 miles from Trim. It is a grey stone castle built over 4 floors with four crenellated main towers. The castle is surrounded by a protective wall and has three entrances one with a gatehouse lodge and stewards house.

Durrow is the site of one of the earliest and most important monastery founded by St Columcille about 550. Largely undisturbed, the site is an early medieval monastic complex of ecclesiastical and secular monuments, visible and sub-surface. The extant monuments at the site include a large ecclesiastical enclosure, five Early Christian grave slabs, a fine mid-ninth century high cross and so more.

Emo Court is a quintessential neo-classical mansion, set in the midst of the ancient Slieve Bloom Mountains. Designed by noted architect James Gandon, it features magnificent gardens and is located just 2.5 km from Emo village and 7 km from Portarlington Railway Station. Architectural features of the building include sash-style windows, pavilions, a balustrade, a hipped roof, and large dome. It is one of the few houses to have been designed by Gandon.

Enniscorthy Castle is situated in Enniscorthy, County Wexford. Construction on the castle commenced in the late 1190s and was first occupied by its Norman owners in 1203 A.D. Now restored and updated, the castle is now home to a new visitor experience that showcases the history of the town and its imposing castle.The Castle has been home to Norman Knights, English armies, Irish rebels and prisoners, and local merchant families and today features interactive exhibitions suitable for all ages

This majestic christian monastry was founded by St Feichin in 630AD. Unfortunately, the only remaining pre-Norman building is St Feichin's Church, which was built in the 12th century, on the foundation of an earlier structure. The site is referenced in the Annals of Inisfallen (AI) as "Repose of Fechtnach of Fobar".

Four Knocks is a Passage Chamber Tomb built about 5000 years ago. It is located 10 miles southeast of Newgrange between Ardcath in County Meath and the Naul in County Dublin. It has a short passage leading into a wide pear shaped chamber with three smaller offset chambers. The original roof was probably a wooden structure supported by a central pole. The name Fourknocks may be from the Irish Fuair Cnocs meaning Cold Hills.