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11 Celtic Ruins and Ancient Sites in Ireland Not to Miss

From coastal castles to farmers’ fields, the landscape of Ireland is punctuated by unique ruins. The remains of early Christian churches, medieval abbeys, and castles give this beautiful county some of its character and reflect its centuries of history. In our three trips around Ireland, we have seen many of its ancient sites and Celtic ruins. Here’s a look at some of the most fascinating Irish ruins we’ve visited.

The Priory of Kells

The Priory of Kells
The Priory of Kells

The massive Priory at Kells is the largest and most important of the Augustinian monastic sites in Ireland. Kells was believed to be founded by Baron Geoffrey FitzRobert in 1193. The priory was attacked and destroyed many times between the mid-1200s and the mid-1300s.

In 1540, King Henry VIII dissolved the priory and divided the lands, which were further dispersed by Oliver Cromwell. Currently, the Priory at Kells is being restored by Ireland’s Office of Public Works (OPW) as part of an initiative to protect the Celtic ruins in the countryside.

The most striking factor of Kells is the lack of visitors. During our nearly two hours exploring the site, we saw only one other visitor – an elderly gentleman who lives nearby walking his dog. That left plenty of time to wander the complex taking photos and imaging what life must have been like here.


Glendalough’s Round Tower, some of Ireland's most beautiful Celtic ruins
Glendalough’s Round Tower

The monastic settlement of Glendalough was founded in the 6th century by St. Kevin and is noted for its massive round tower standing on the valley floor in the Wicklow Mountains. Glendalough is on the tourist trail and makes a very popular lunch stopover for folks driving from Dublin to Kilkenny.

Glendalough is special for us because it was our very first Celtic ruin on our first trip Ireland. We were disappointed because it was pouring rain on the day we visited. On our second trip, we added a day to our Ireland itinerary so we could revisit Glendalough – hopefully in better weather. This trip did not disappoint.

Baltinglass Abbey

Between Glendalough and Kilkenny is the small village of Baltinglass. As we planned our route, I noted on the map that there was a ruin in the town. Intrigued, we decided to stop for a visit, which turned out to be one of the great adventures of our trip.

The Baltinglass Abbey is not manned by staff from the OPW and only a rudimentary sign at the entrance gives any information about the site. The site is next to a modern church (St. Mary’s Church), and we arrived on a Saturday as the congregation was deep in preparations for the annual harvest feast. The parishioners are very proud of both the ruins as well as the modern church and gave us an extensive tour of both.

The Ruins of Baltinglass Abbey
The ruins of Baltinglass Abbey

One of the parishioners spoke up and indicated he had a booklet about the site and wanted us to have it (the booklet is called Baltinglass and Its Abbey by The Rev. Canon Claude Chavasse). We were to follow him in our rental car to his house, which was “just over there” – a flourish of the arm in the general direction of the town.

But Mr. Carpenter’s house was not in town. So, we went over the river and through the woods before arriving at his stunning farm in the countryside. Meeting locals is always a highlight of a trip and meeting him and seeing his home was a fantastic adventure.

From the booklet, I learned that Baltinglass Abbey was completed in the 12th century in the Irish Romanesque style. At one time, it was not only one of the richest in all of Ireland but one of the wealthiest in all of Europe.

The Rock of Cashel

The Unique Ruins on the Rock of Cashel
The unique ruins on the Rock of Cashel

Few sites in Ireland have as much historical significance as the Rock of Cashel. On this site above the Tipperary plain, St. Patrick converted and baptized the King of Munster in the 5thcentury. For centuries, the Rock was the seat for the Kings of Munster – and was fought over by the various Celtic tribes.

In the early 1100, one of the Kings of Munster (Muirchertach Ua Briain) donated the Rock to the Catholic Church, and the rest is history. The round tower dates from ~1100 and the other buildings were added shortly thereafter.

The Rock of Cashel is one of our favorite places to visit in Ireland, so we’ve visited on each of our trips. There’s just something magical about this place towering above the plains.

Hore Abbey

Stone ruins of a medieval abbey
The ruins of Hore Abbey

Hore Abbey is just a stone’s throw from the Rock of Cashel, but it is a very different site. Originally a Benedictine abbey, it was founded in 1266. But just a few short years later in 1272, Archbishop David McCarvil expelled the Benedictines when he dreamed that they were trying to murder him. At least that’s what legend says was the reason.

The Cistercians assumed control and oversaw operations there for centuries. Now, it’s a beautiful site to explore with arches, niches, and lots of headstones. In the middle of a cow pasture, a visit here can be a little bit messy.

Corcomroe Abbey

Cross marker inside the stone ruined walls of a medieval abbey
Inside Corcomroe Abbey

The Cistercians preferred isolated locations for their monasteries. Thus, this spot in what is now County Clare fit the bill for a new place to worship and live when Donal Mor O’Brien, King of Thomond, founded Corcomroe Abbey here in 1194.

Though the property has been out of use for at least 400 years, the Gothic ruins endure. Inside, visitors will find detailed carvings that are among the best the Cistercians left in Irish churches. Additionally, the near-life-sized effigy tomb of Conor O’Brien, who died in 1267, can be seen in the chancel area. It is the final resting place of the grandson of Corcomroe’s founder and one of very few such tombs honoring an Irish chieftain.

Grianan Aileach

Grianan Aileach in County Donegal, some of Ireland's ancient Celtic ruins
Grianan Aileach in County Donegal

One of the defining characteristics of countryside is its ring forts, the curious ancient ruins in Ireland. We first discovered them on The Ring of Kerry. Our innkeepers in Derry recommended we visit Grianan Aileach atop a hill just west of the city and back in the Republic of Ireland (County Donegal).

Grianan Aileach was the seat of the Kingdom of Aileach, but was destroyed by the King of Munster Muirchertach Ua Briain in 1101 (the same King who donated the Rock of Cashel to the Catholic Church).

We arrived before the posted the opening time, but the gates were already open. This ring fort is completely intact (restored in the mid-1800s) and offers incredible 360 degree views of the surrounding countryside. Grianan, like other ring forts, just feels so ancient.

Dunluce Castle

Stone ruins of an ancient castle on a hilltop overlooking the ocean
Dunluce Castle perched on the coast

On the Antrim Coast Road not far from Giant’s Causeway, the majestic ruins of Dunluce Castle hang on the cliff of a small islands just offshore.

Built in the 13th century by the Earl of Ulster, the castle was ruled by the McQuillan and MacDonald clans for centuries. It has been over 200 years since the castle’s north wall crashed into the sea below, but that hasn’t dampened people’s interest in the dramatic structure.

Today, the ruins of Dunluce Castle are a popular picnic spot on the Causeway Coastal Route.

Jerpoint Abbey

Courtyard and tower of the Jerpoint Ireland abbey ruins
The ruins of Jerpoint Abbey

Jerpoint Abbey was completed in 1180 by the King of Osraige and was dedicated to the Blessed Virgin. Like Baltinglass, Jerpoint was a Cistercian monastery. In fact, Jerpoint was a derivative “daughter” monastery that actually reported into the “mother” Baltinglass. With stone depictions of medieval knights and a decorated cloister, there is lots to see here.

Staigue Fort

The Staigue fort
Staigue ring fort

Like Grianan Aileach, the Staigue ring fort is a prehistoric structure dating from around 300 AD and overlooks Kenmare Bay. Of all the ancient sites in Ireland, this ruin has the best preserved example of interlocking stone work. Local lore has it that this structure might have been some kind of trading post.

During our visit, we found the fortification to be open for exploring, by both man and sheep. Given its location on the popular Ring of Kerry, this is one of the most visited Celtic ruins.

Gallarus Oratory

The Gallarus Oratory on the beautiful Dingle Peninsula in Western Ireland
Gallarus Oratory

This unusual building on the Dingle Peninsula overlooking Ard na Caithne/Smerwick dates from the 12th century. This small structure is believed to be an early Christian church or chapel. Discovered in 1756 by Charles Smith, there has been some controversy over the age, origins, and purpose of the building.

This is the only intact oratory in Ireland. While others may have existed at one time (and local writings and lore attest to that), this is the only one to exist.

We visited on a cool, windy morning and found the place to be very remarkable. The views of the nearby farms (with sheep!) and of the harbor below makes this one of the more remarkable Celtic sites in Ireland.

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Wednesday 15th of June 2022

Ballintubber Abbey was my favorite. Pierce Brosnan was married there, as well as many Irish couples. i hope to return someday.

Ana O

Monday 17th of August 2015

This is thoroughly fascinating. Thanks for sharing the beautiful photos and the information. BTW, is Kells Abbey related in any way to the Book of Kells? I wonder if it's where the manuscript was copied and illuminated.


Tuesday 25th of February 2014

I love seeing sunshine-y photos of Ireland! All fantastic shots!

Laura Longwell

Wednesday 26th of February 2014

Thanks! We were very lucky to have great weather!

Londoner Kate

Thursday 9th of January 2014



Thursday 9th of January 2014

Gorgeous!! I've always wanted to go to Ireland!

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