When it comes to the island of Ireland’s historic treasures, most first-time visitors flock to blockbuster attractions like the Cliffs of Moher, the Rock of Cashel, or Blarney Castle. And while those iconic sites are absolutely worth seeing — that’s why they feature on many of our small-group tours of Ireland — some of the most powerful, memorable moments happen off the beaten path.
This guide is for curious travelers who want to dig a little deeper into Ireland and Northern Ireland’s past. Whether you’re a history buff, a lover of Celtic legend, or looking to reconnect with your Irish heritage, these lesser-known historical sites offer unforgettable experiences with fewer tourists and a whole lot of atmosphere.
If any of the historical hidden gems in Ireland and Northern Ireland mentioned below capture your imagination, but they don’t appear on one of our pre-planned itineraries, don’t worry! With our tailor-made Ireland tours, our expert trip planners can create a bespoke journey through the Emerald Isle in line with your needs. Please just contact us if you have any questions!
Dunluce Castle – Perched on the Edge of History
Teetering dramatically on the cliffs of County Antrim in Northern Ireland, Dunluce Castle is one of Ireland’s most haunting ruins. This 13th-century fortress was once the stronghold of the powerful MacDonnell clan and is steeped in legend, including tales of a castle kitchen collapsing into the sea during a storm.
Though it’s just a short drive from the Giant’s Causeway, many travelers miss it entirely. Don’t be one of them! It’s a must-see if you’re traveling the Causeway Coastal Route. If you want to add Dunluce Castle as a stop on your journey through Ireland and Northern Ireland, you can include it on either the Wild West and North Ireland Tour or the Ultimate Ireland 10-day Tour.
Dún Aonghasa – Ireland’s Prehistoric Edge
Located on Inis Mór, the largest of the Aran Islands, Dún Aonghasa is a prehistoric cliff fort that dates back over 3,000 years. Set on a dramatic clifftop with nothing but the roaring Atlantic below, it’s one of the most awe-inspiring historic sites in Ireland — and one of the oldest.
Its remote island setting makes it feel like you’ve stepped into another world. Despite its significance, Dún Aonghasa remains a hidden gem to many international travelers, but you can see it on our Ireland to Island 7-Day Tour or a custom West Coast itinerary.
Ross Castle – Lakeside Legacy in Killarney
Overlooking the calm waters of Lough Leane in Killarney National Park, Ross Castle is a 15th-century tower house with roots in the Gaelic O’Donoghue clan. It later played a key role in the resistance against Cromwellian forces. The castle’s defenders, led by Lord Muskerry, took confidence in a prophecy: the stronghold could only be taken by a ship. General Ludlow, a Cromwellian commander, learned of this and duly launched a large boat on the lake. Upon seeing the vessel, the resistance assumed the prophecy was being fulfilled. Their surrender came soon after.
Ross Castle is a scenic, moody spot often missed by those racing around the Ring of Kerry, but it’s well worth a stop, especially if you love castles with water views. If you’ve got your heart set on an independent road trip and Ross Castle is a must-visit for you, consider our Ultimate 10-Day Self-Drive Ireland Tour.
Cahir Castle – Fortress of the Kings
Tucked along the River Suir in County Tipperary, Cahir Castle is one of Ireland’s largest and best-preserved medieval fortresses. It’s a quiet gem with working defensive mechanisms like a portcullis and battlements that you can explore freely.
Often overshadowed by the nearby Rock of Cashel, Cahir Castle offers a more relaxed and equally rich experience, and with fewer visitors. Our recommendation? Visit them both! They’re both fascinating historical sites in Ireland, offering a glimpse of our country’s past.
Conveniently located on the direct road from Dublin to Cork, it’s easy to add Cahir Castle (and the Rock of Cashel, which is only around a 20-minute drive away) to your own custom Ireland tour! Alternatively, consider our Magical Southern Ireland Tour, which includes Cahir Castle as a stop.
Jerpoint Abbey – Monastic Peace and Forgotten Carvings
A short drive from Kilkenny lies Jerpoint Abbey, a 12th-century Cistercian monastery with striking stone carvings, peaceful cloisters, and crumbling walls full of stories. It’s a tranquil, photogenic site that rewards slow wandering. While nearby Kilkenny draws more attention, this quiet ruin offers a powerful connection to Ireland’s monastic past.
You can easily add Jerpoint Abbey to any custom tour of Ireland with Overland! Looking for more one-of-a-kind landmarks for your Irish experience? Check out our blog Some Unique Attractions to See in Ireland for even more inspiration!
Grianán of Aileach – Where Myth and Kingdoms Meet
Standing high above County Donegal with views across Lough Swilly and the Inishowen Peninsula, Grianán of Aileach is a ringfort steeped in mystery. Once the seat of the Kingdom of Ailech and a royal site in Gaelic Ireland, it’s tied to both legend and early kingship. This stunning dry-stone structure has a diameter of around 23 meters, and its walls reach up to five meters in height. Perhaps most remarkably of all, this ancient structure (it dates back to around the 6th or 7th century CE) is built on the summit of the 244-meter-high Greenan Mountain.
The panoramic views are reason enough to visit. The lack of crowds and sense of timelessness seal the deal.
Grianán of Aileach is a short drive west of Derry, so we can include it in a custom tour of the north of the Emerald Isle. It also features in some of our self-drive tour packages of Ireland, including the Coast to Coast Driving Tour of Ireland.
Hill of Uisneach – Ireland’s Sacred Center
Often referred to as the mythological center of Ireland, the Hill of Uisneach was where the five ancient provinces met and where ancient Bealtaine fire festivals were held. It’s said to be the final resting place of the goddess Ériu, from whom Ireland gets its name. Peaceful and powerful, Uisneach offers spiritual depth for those drawn to Ireland’s mystical past.
The Hill of Uisneach sits between Dublin and Galway, albeit off the main M6 connecting the two cities. With this easy accessibility, we can include a stop at this unique historical site on one of our tailor-made tours of Ireland with a customized route between the east and west coasts.
Small-Group and Custom Ireland Tours for Every Need!
We hope you’ve found our picks for the best lesser-known historical sites in Ireland inspiring. Which ones do you want to visit on your own experience in the Emerald Isle? Browse our range of small-group tours of Ireland and see which of your favorite sites feature in our pre-planned itineraries. And remember, if you can’t find what you’re looking for, our tailor-made Ireland tours are the perfect way to make your dream trip a reality.
Do you have any questions for the Overland team? Please don’t hesitate to get in touch for the answers you need.
