Standing on a natural terrace on the island, with the ground climbing away to the west and falling off to the east, you would have no reason to pause. The enclosure is entirely invisible at ground level, detectable only by the faint disturbances it leaves in the earth's magnetic field.

What is known about the site comes from a magnetometer survey, a geophysical technique that measures subtle variations in soil magnetism caused by buried features such as ditches, pits, or burnt material. That survey, cited by Cooney in 2009, revealed the outline of an elongated oval or sub-rectangular structure, along with a strong magnetic anomaly consistent with a concentrated area of burning. Whether that burning represents a hearth, a destruction event, or something more deliberately ceremonial cannot be said with certainty. The enclosure itself, a term used broadly for any defined area bounded by a bank, ditch, or wall, could date to almost any period of prehistory or early history. No field inspection has been able to confirm or elaborate on the magnetometer results, leaving the structure in an uncertain state, known to exist in some form beneath the surface but otherwise uncharacterised.

Accessing Lambay Island is not straightforward. The island is privately owned and not open to casual visitors, so any trip requires prior arrangement. For those who do reach it through legitimate means, the terrace in question offers no obvious marker or signage. The value here is less in what you can observe than in the idea itself: that the island's archaeology extends well beyond what is mapped or visible, and that instruments rather than eyes are sometimes the only means of reading a landscape. Geraldine Stout compiled the record in August 2011, and it remains one of those entries that raises more questions than it answers.