Most souterrains, the stone-lined tunnels built across early medieval Ireland as refuges or cool storage chambers, were dug and constructed by people. This one, it turns out, simply borrowed from what was already there.

According to local knowledge passed on by M. A. Timoney, the souterrain at Foyoges is an extension of a natural cave, and water still moves through natural rock at its base. That detail changes how you read the place. Rather than an entirely engineered structure, it appears to be a case of early builders recognising and adapting a geological feature, connecting a man-made passage to a cavity that the landscape had already formed. The proximity to the church and graveyard, themselves recorded as separate monuments on the same site, suggests a cluster of activity here across different periods, though how and whether the souterrain relates directly to those religious structures is not certain. What is clear is that the site sits at a point where the constructed and the geological quietly converge, water running beneath the roots of a field that has been used, in one way or another, for a very long time.