Excavations carried out between 1997 and 2001 at a location on the island known as the Eagle's Nest brought the monument to light. Archaeologists uncovered a series of pits that had been covered over with stones and successive layers of sediment, with stone settings worked into the fabric of the mound itself. What made the find especially striking was the discovery of a hoard within the mound's make-up that included an Orcadian type macehead. A macehead is a prestige stone object, typically a carefully shaped and perforated head fitted to a handle, associated in Irish and British prehistory with ceremony and high social status rather than everyday use. The Orcadian type takes its name from the style associated with Orkney in northern Scotland, where such objects have been found at major Neolithic monuments including Skara Brae. The presence of one on Lambay points toward long-distance connections in the Neolithic period and suggests the island held some significance well beyond its immediate geography. The excavation findings were discussed by Gabriel Cooney in 2003, and the record was compiled by Geraldine Stout.

Lambay is privately owned and not open to casual visitors, so the mound at the Eagle's Nest is not accessible in the way that a mainland monument might be. Anyone with a particular research interest would need to pursue access through appropriate channels. For those approaching the subject from a distance, the Cooney 2003 publication remains the primary reference for the excavation's findings, and the mound is a useful reminder that islands off the Irish coast were not marginal places in prehistory but active nodes in networks that stretched, in this case, as far as the northern isles of Scotland.