A serpentine pattern of low stone walls snakes toward the ruins of O’Brien’s Castle (Caisleán Uí Bhriain in Irish Gaelic). The 14th-century fortress stands atop the highest point of the remote island of Inisheer.
As soon as you arrive on Inisheer, the smallest of the three Aran Islands off Ireland’s west coast in Galway Bay, you’ll enter a small, primarily Gaelic-speaking fishing village of about 250 residents. From there, you’ll see the castle towering stoically on a hill in the distance.
Not much is known about the structure, but it’s believed it was once a tower house. It’s likely it was a stronghold of the O’Brien clan, which was prominent in the area.
Follow the old stone walls from the village, and you’ll soon arrive at the ruins. It’s easy to miss, but on the way up to the castle a Bronze age burial mound known as Cnoc Raithní can be spotted on the side of the path as well.
Once at the castle, you can slip through its narrow entrance to explore its interior. You’ll be able to see the parts of the second and third stories that still survive, as well as some of the partially moss-covered interior rooms. The ruins have collapsed in such a way that a climb to the top of the tower is very do-able and provides a panoramic view of Inisheer, the surrounding bay, and some of the other ruins on the island that are harder to spot from ground level, including a medieval cemetery and the partially underground ruins of St. Kevin’s church, which features an extremely old stone carving of Christ.