The word itself comes from the French for "underground," and these structures are found scattered across Ireland in their hundreds, dry-stone lined and carefully roofed with lintels, often connected to nearby ringforts or settlement sites above ground. That one exists at Annagh is, for now, almost all that can be said with certainty.

The specific history of this particular souterrain, its dimensions, its condition, who may have built it and when, remains formally undocumented in publicly available records. It sits on the map as a classified monument, acknowledged but not yet described in any detail that has been made openly accessible. This is not unusual for Ireland, where the sheer density of archaeological sites means that cataloguing inevitably outpaces the production of detailed records. What the classification itself tells us is that something was found here, something significant enough to warrant formal recognition, even if the particulars of that discovery have not yet entered the public domain.