The magnificent ruins of the great O'Brien stronghold of Lemaneagh stand on the southern fringe of that limestone wilderness known as the Burren. It is a lonely place, some call it bleak, and perhaps a surprising location for a splendid four-storey, high-gabled, early seventeenth-century mansion with rows of large mullioned and transomed windows.

The early part of the building at the east end is, by contrast, a rather grim five-storey tower c.1500, with narrow slit openings for windows, a tier of small chambers and a spiral stair.

Its entrance passage, with drawbar holes for inner and outer doors, was probably later reserved for servants, as the gabled mansion had its own front door.

The eastern portion of the castle is a 5-storey tower built about 1480. A four-storey mansion was added to the west of the tower in the 1640s, and it has some mullioned windows. This monument is visible from the road but not accessible.