This massive fortification, covering over eight hectares, consists of four concentric enclosures that ripple outward from a central stone-built citadel.

The innermost sanctuary, roughly 55 metres across, is marked by a distinctive ring of large boulders that still stands today, with what appears to be the remains of an ancient dwelling hut at its heart. Archaeological investigations have revealed that this wasn't just any ordinary settlement but part of a remarkable cluster of up to nine hillforts surrounding the modern town of Baltinglass, suggesting this area held tremendous strategic importance in prehistoric times.

The site's complexity becomes truly apparent through modern technology. Geophysical surveys using magnetic gradiometry have unveiled the ghostly outlines of massive ditches and banks, some of which appear to have been destroyed by fire in antiquity. Aerial photographs taken by Cambridge University in the 1960s first captured these features as cropmarks, revealing the full extent of what had been largely invisible from ground level. The surveys show evidence of possible wooden palisades and hut structures within the enclosures, painting a picture of a substantial fortified community that commanded panoramic views across the Wicklow Mountains and surrounding countryside.

Recent excavations by University College Cork have begun to unlock the site's secrets, uncovering substantial defensive ditches and recovering charcoal samples for radiocarbon dating, though the results are still pending. A single sherd of prehistoric pottery represents the only artifact found so far, but the scale and sophistication of the earthworks speak volumes about the people who built this fortress. Unfortunately, land reclamation in 1961 damaged portions of the site, and much of the outer defences have been levelled over the centuries, leaving only subtle traces in the landscape and the enduring stone circle at the summit as testament to this ancient stronghold.