Cartographers working on the Ordnance Survey in 1841 and 1842 recorded a circular enclosure here, the classic shape of a rath, an earthen ringfort of the kind built across Ireland throughout the early medieval period as enclosed farmsteads for families of some local standing. The same enclosure appeared again on the 1914 revision. By the time anyone came to look more carefully, however, the fort itself had been levelled.

What makes the Lahesheragh site particularly notable is not the ringfort but what lay beneath it. The rath contained a souterrain, an underground stone-built passage or chamber system used in early medieval Ireland for storage, refuge, or both. When the Office of Public Works inspected the site in 1974, they found the fort almost completely destroyed and the souterrain in serious trouble. A bulldozer had broken through the roof of one of the chambers. The structure had been T-shaped, an unusual configuration, and the surviving chamber measured approximately 6.2 metres long, 1.2 metres wide, and just 80 centimetres in height, low enough that anyone inside would have been moving on hands and knees. No visible trace of the souterrain remains today.

There is nothing left to see at Lahesheragh in the conventional sense. The value of the site now lies almost entirely in the record of what was there, and in the particular melancholy of an inspection report that arrived, as they so often do, just after the damage was done.