The trees were planted inside the central platform of a prehistoric ring-barrow, a type of funerary mound in which a raised earthen platform is encircled by a fosse, or ditch. The overall monument measures around 25 metres in diameter, with the central platform rising to roughly 0.9 to 1 metre at its highest. Spoil heaps from field-clearance work have been piled along the edge of the fosse over the years, adding to the general obscuring of the original form.

When the archaeologist Duignan examined the site in 1953, he could still make out traces of a bank that had been demolished in places. By the time of more recent surveys, even those traces had disappeared from the surface entirely. What survives now is, in practical terms, an earthwork that has been slowly absorbed into the working landscape around it. The trees, the spoil heaps, and the general wear of agricultural use have combined to reduce a once-deliberate funerary construction to a faint irregularity in the ground. What makes the Moneen barrow particularly interesting, though, is not its own condition but its context. At least three other ring-barrows lie within roughly 260 metres in various directions, suggesting that this area of County Galway was once a meaningful concentration of prehistoric funerary activity, a loose cluster of monuments that would have given the landscape a very different character to the anonymous pastureland it presents today.