169 Old Ruins to Explore in Leinster

The Boyne Viaduct, a 30-metre-high railway bridge, or viaduct, that crosses the River Boyne in Drogheda, carrying the main Dublin–Belfast railway line. During World War II, the viaduct was identified by the British as being of great strategic importance as part of the British plans for a counter-attack following a German invasion of Ireland.

It is classified as a portal tomb by archaeologists and there are approximately 174 of these monuments in the country. The tombs generally consist of two large portal-stones defining the entrance and a back-stone, all of which support the cap-stone. The tomb is listed as a National Monument. Known as the Kernanstown Cromlech, sometimes spelled as Browneshill Dolmen, it is sited on the former estate house of the Browne family from which it takes its name.

Brú na Bóinne is one of the most important prehistoric megalithic sites in Europe drawing thousands of visitors daily. Each of the tombs has their own myths to explore against the beautiful backdrop of the gently meandering River Boyne. The archaeological landscape within Brú na Bóinne is dominated by the three well-known large passage tombs, Knowth, Newgrange and Dowth, built some 5,000 years ago in the Neolithic or Late Stone Age.

This National Monument, is a well-preserved 15th century Norman tower house with a round gate tower, situated in the parish of Burnchurch, County Kilkenny, Ireland. It is said to have been built and owned by the Fitzgeralds of the house of Desmond in 15th century and continued to be occupied until 1817.It is known for being one of several Irish towers with the slightly narrower sides of the castle extending up an additional floor, creating in essence a pair of tower wide turrets.

A majestic castle situated in the townland of Carbury, on the borders of Kildare and Offaly. The area is dominated by the ruins of this great Tudor mansion set atop Carbury Hill, which was also known as Fairy Hill. It is a typical tower house- a single, multi storied rectangular building, with various annexes containing staircases and latrines.

Carlingford Heritage Centre is located in a beautifully restored Medieval Church which has been a vital part of Carlingford's historical landscape since the 13th century. Discover Carlingford’s heritage and experience the history of the region. Visitors can learn about the village from its foundation to its prosperous years and right through to modern day. The historical exhibition is embellished with maps, drawings, illustrations and so more.

This is one of the most important Anglo-Norman castles in Ireland situated beside the banks of trivers Barrow and Burrin near the centre of Carlow Town. It was thought to have been built by William de Marshal. At one time Carlow was an important and strong military fortress, strategically sited at the confluence of the rivers, and the castle withstood repeated attacks in 1494 and 1641.

Castledermot Abbey is a ruined Franciscan friary in Castledermot, County Kildare, in the Republic of Ireland. It was founded in about the year 1300. A previous monastery was founded on the same site by Diarmait, a son of Áed Róin, King of Ulster, in the ninth century AD. The solid stonework is well preserved, seeming as secure and strong as the day it was first constructed.

This ancient church at Castledermot was formerly known as Díseart Diarmada, meaning Dermot’s hermitage. The monastery was raided by the Vikings in the 9th century, but continued its existence at least until the 12th century. All that is left today is a splendidly reconstructed Romanesque doorway, which came from a church that has since vanished.

A well preserved ceremonial circle stands four and half km south of Donard village in Castleruddery Lower. This site consists of an inner circle of twenty nine large stones, some standing erect, others lying surrounded by a flat earthen bank. Two extremely large quartz boulders on the eastern side, possibly mark the entrance. Locally, the circle is thought to have special healing properties.

A majestic country house set amongst beautiful eighteenth-century parklands on the banks of the Liffey in Celbridge, County Kildare.It formed the centrepiece of a 550-acre estate. Sold to developers in 1965, the estate is now divided between State and private ownership. It was home to a significant collection of paintings, furnishings and objets d’art. Highlights include three eighteenth-century Murano-glass chandeliers and the only fully intact eighteenth-century print room in the country.

This is an impressive structure that dates back to 1285. Explore the cathedral and climb to the top of the magnificent 30 metre high round tower. The present building dates from the 13th century and is the second longest cathedral in Ireland. The cathedral contains some 16th-century monuments. The architectural style of the cathedral is Early Gothic and is built of limestone.

A majestic Roman Catholic cathedral located in Mullingar.The cathedral, which boasts a beautiful modernised Renaissance style, opened in 1936 and is the seat of the Bishop of Meath.The cathedral is both the cathedral church of the diocese of Meath and the principal centre of worship in the catholic parish of Mullingar, including parts of counties Meath and Westmeath.

The Cathedral of the Assumption is both the cathedral church of the Roman Catholic Diocese of Kildare and Leighlin and the parish church for the cathedral parish. Located in Carlow town, the cathedral was dedicated to the Assumption of the Blessed Virgin Mary in 1833. It is known for its beautifully detailed 151 ft spire which is one of the highest points in the town.

A Gothic-style castle located in County Offaly, Ireland, bordering the town of Tullamore, near the River Clodiagh. It is considered one of the finest of its type in the country. The castle itself is believed to be the most haunted building and grounds in Europe, with it appearing on Living TV's Most Haunted and Fox's Scariest Places on Earth.

The Church of Saints Peter and Paul, Athlone is a Roman Catholic parish church situated in the town of Athlone, County Westmeath. The church was constructed between 1932–39, and stands on the banks of the River Shannon.It is notable for its stained glass windows, produced in the Harry Clarke workshop by Richard King.

Clara Castle is a tower house located in County Kilkenny, Ireland. It was built in the sixteenth century by the Shorthall family. It is five storeys tall with a vault above the third floor. The building retains many of its original oak doors and floor beams. There is a murder-hole above the entrance, which is also protected by a yett and drawbar.

Clochafarmore is a menhir and National Monument in County Louth, Ireland. It is located 1.4 km east-northeast of Knockbridge, Dundalk on the left bank of the River Fane. This standing stone is traditionally associated with the death of the legendary hero Cúchulainn. Lugaid mac Con Roí has three magical spears made, and it is prophesied that a king will fall by each of them.

Clomantagh Castle is part of a unique settlement of tower house, farmhouse and bawn. Originally constructed in the 1430s, additional buildings and outbuildings were added in the subsequent centuries - including a connected 19th century farmhouse. The castle was subject to renovations in the late 20th century and is now managed as a holiday rental property.

This sixth century monastic site, located on the banks of the River Shannon is home to three high crosses, a cathedral, seven churches and two round towers. This great monastery was founded in 548- 9 by St. Ciarán Mac a tSaor. It became a great centre of religion and learning, visited by scholars from all over the world. Many historical manuscripts, including the 11th-century Annals of Tighernach and the 12th-century Book of the Dun Cow, were written here.