What looks at first like a modest rise in a field is in fact a ringfort, a type of enclosed settlement built in their thousands across early medieval Ireland, typically between the sixth and tenth centuries. This one at Laheen measures roughly 33 metres across the central platform, but the full monument, once you account for the surrounding earthworks, extends to nearly 69 metres from north to south.

The site is defined not by dramatic masonry but by earth and negative space. A broad, overgrown fosse, the defensive ditch that encircles the inner platform, runs up to eight metres wide at its top, and beyond that sits a flat-topped external bank that adds further bulk to the whole arrangement. Slight traces of an inner bank survive on the north-east and south-west sides, though much of it has been worn down over time. What gives the site particular interest is the evidence of a second, outer fosse, visible in stretches to the north-north-west and south-east, suggesting the enclosure was more elaborately defended than a simple single-ditched ringfort. Ringforts with two or more concentric ditches, sometimes called multivallate forts, are generally thought to indicate higher-status settlements. There are two gaps in the outer bank: a narrow one on the west-north-west side, and a wider one on the south-east with a rough causeway that is likely the original entrance, though it appears to have been widened at some point. A small canalised stream runs roughly north to south about 30 metres to the west, close enough to have been a practical resource for whoever once lived within these banks.