These underground structures, built without mortar and roofed with large stone lintels, were dug into the earth beside or beneath settlement sites. Depending on the example, they served as refuges, storage spaces for perishables, or places of concealment, and their presence in a landscape is usually a quiet signal that a farming community once worked the ground above them.

The Knockaloura souterrain is recorded as a monument, though the details that would fill in its particular story, its dimensions, its state of preservation, how and when it was identified, remain unavailable at present. What can be said is that Galway contains a scattering of these structures, and that their distribution tends to follow the patterns of early Christian settlement, often turning up near ringforts or the earthwork enclosures associated with the same period. A souterrain discovered in pasture or bog can be the only surface trace of a community that otherwise left no standing walls.