What was once a subrectangular structure of considerable scale, roughly 97 metres along its north-east to south-west axis and about 76 metres across, is now so thoroughly absorbed into the surrounding fields that its defining wall survives only as a low stony mound running along the present field boundaries. To a passing eye, it reads as little more than a slight irregularity in the ground.

Enclosures of this kind, typically defined by a drystone wall, are a recurring feature of the Irish countryside, and their functions varied widely, from settlement and farming to ritual or defensive use depending on their period and context. The name Caherglassaun itself contains the element "caher" (from the Irish cathair), a term commonly used in Connacht for a stone-walled enclosure or ringfort, which hints at the broader tradition of enclosed settlements in this part of Galway. The interior of this particular example has been further divided by later field walls, making it difficult to read the original layout, and dense growth of briars and thorn bushes now covers much of the site. What the Galway Archaeological Survey, working through University College Galway, recorded here is less a monument than a memory of one, its outline still just legible if you know where and how to look.