That inaccessibility is, in its own way, part of the story. The vegetation has effectively sealed off a space that was once, in early medieval Ireland, the centre of a farmstead, a place where a family or small community lived, stored food, and kept livestock behind an encircling bank of earth.

A rath, as this type of ringfort is also known, is one of the most common archaeological monument types in Ireland, with tens of thousands recorded across the country. They were built and used roughly between the fifth and twelfth centuries, and their defining feature is a raised earthen bank, sometimes one ring, sometimes two or three, enclosing a circular area. This example at Ardagh measures around 23 metres in diameter, enclosed by a bank that still stands to an internal height of 1.3 metres. Outside the bank runs a fosse, a defensive ditch, here reaching a maximum depth of 1.5 metres. The fosse has partially silted up on the northern and north-eastern sides, while the south-eastern stretch has become waterlogged over time. A causewayed entrance, essentially a gap left in the ditch to allow passage across it, survives on the eastern side at 2.2 metres wide, which is a fairly typical width for a single-person or livestock entrance of this kind. The bank itself is heavily overgrown, softening what would once have been a sharper, more deliberate earthen profile.