Many who visit Grianan of Aileach in Donegal enjoy the views but fail to take the time to understand its fascinating history.
Boasting breathtaking views that take in everywhere from the Inishowen Peninsula to Glenveagh, An Grianan Fort is very accessible thanks to a car park right next to it.
It’s situated on top of Greenan Mountain, where it is believed to have been built during the 6th or 7th century.
Once the stronghold of the formidable Northern Uí Néill dynasty, the fort now stands as a poignant reminder of ancient Ireland.
Quick need-to-knows about Grianan of Aileach
Although a visit to an Grianan Fort is fairly straightforward, there are a few need-to-knows that’ll make your visit that bit more enjoyable.
1. Location
You’ll find the fort on Greenan Mountain a 20-minute drive from Derry City and a 25-minute drive from both Letterkenny Town and Buncrana.
2. Parking
There’s a generous amount of parking at the top of the hill (here on Google Maps). It’s then a 2-minute walk to the fort.
3. Opening times
The opening times for Grianan of Aileach were previously all over the place. However, as of early 2024, there is access to the fort from 08:00 to 18:00.
4. No entrance fee
Although the likes of Donegal’s Slieve League Cliffs recently introduced parking charges, that’s not the case here – there is no entrance fee for An Grianan Fort.
The history of An Grianan Fort
Photos via Shutterstock
Few who visit Grianán of Aileach fail to get a sense of stepping back in time as they walk around its ancient walls.
Like many corners of Donegal, An Grianán Fort is rich in history and has a fascinating tale attached to it.
Construction and purpose
Perched in an enviable position at the top of Greenan Mountain, Grianán of Aileach offers views of everywhere from Glenveagh National Park and Derry City to Lough Foyle and beyond.
The fort is surrounded by a dry-stone wall that comes in at around 5 metres tall and hugs an area that measures 23.5 metres in diameter.
It is thought to have been built during the 6th or 7th century by the kings of the Cenél nÉogain, a branch of the powerful Northern Uí Néill dynasty.
Their kingdom was the Inishowen Peninsula, and from their fortress they could gaze out across all that they conquered.
The turbulent 12th century
During the 12th century, Muirchertach Ua Briain, the King of Munster, embarked on a six-week campaign into Ulster.
His mission was clear: to challenge the king of the Cenél Eogain at the time, Domnall Mac Lochlainn, and to achieve what is great grandfather, Brian Boru, did before him – become the High King of Ireland.
However, it proved to be no easy task.
Muirchertach’s progress was stopped on several occasions by the diplomatic efforts of the abbot of Armagh who brokered peace 6 times.
However, despite the pair being evenly matched, An Grianán Fort was destroyed in 1101.
Reconstruction and excavations
It wasn’t until the 1870s that Greenan Mountain’s famous fort received some much needed exploration.
Walter Bernard, an archaeologist from Derry, discovered a range of artefacts, including a large stone with a central hole, animal bones, and a chequered slab that may have been a form of gaming board.
The walls of the fort, which were in ruin, were rebuilt and raised to around 6 feet in height.
The St. Patrick connection
The Tripartite Life of Patrick tells of Ireland’s Patron Saint, St. Patrick, and his visit to An Grianan Fort.
It explains that the Saint visited the fort and blessed it, leaving a flagstone at the site.
There is a well on the slopes of the fort that is dedicated to the Saint.
Mythology
The fort is also mentioned in Irish mythology.
Legend tells that it was built by the Dagda – one of the most powerful Celtic Gods and the King of the Tuatha Dé Danann – as a burial place for his son, Aedh.
The Book of Lecan explains that Aedh was slain by Corrgend of Cruach after Aedh had an affair with his wife.
What to do at Greenan Mountain
Aside from the historical importance of the site, many people make a trip up to An Grianan of Aileach simply to enjoy the views.
The views alone are worth the visit with the incredible positioning of the fort on a cleared hilltop providing a complete 360-degree panorama.
From the top of the terraced walls on a clear day, you can see across counties Donegal, Derry and Tyrone.
It also offers spectacular views of Lough Foyle and Lough Swilly, with one of the most iconic photographs from the fort featuring Inch Island off the coast of Donegal.
Note that it can get quite wild and windy on Greenan Mountain so make sure to dress appropriately.
Places to visit nearby
One of the beauties of An Grianán Fort is that it’s a short spin away from many of the best places to visit in Donegal.
Below, you’ll find a handful of things to see and do a stone’s throw from Greenan Mountain!
- Wild Ireland (15-minute drive): A unique animal sanctuary that’s home to rescued animals including bears, wolves, lynx and eagles
- The Inishowen 100 (start at the fort): A 160km or 100 miles drive that visits the best of the peninsula, including Malin Head
- Derry City (20-minute drive): A city steeped in a history that many often miss
Keith O’Hara has lived in Ireland for 35 years and has spent most of the last 10 creating what is now The Irish Road Trip guide. Over the years, the website has published thousands of meticulously researched Ireland travel guides, welcoming 30 million+ visitors along the way. In 2022, the Irish Road Trip team published the world’s largest collection of Irish Road Trip itineraries. Keith lives in Dublin with his dog Toby and finds writing in the 3rd person minus craic altogether.