A rath, or ringfort, is essentially an enclosed farmstead from early medieval Ireland, typically defined by one or more banks and ditches thrown up around a central living area. They are among the most common archaeological monuments in the country, numbering in the tens of thousands, yet each one represents a specific household, a specific patch of ground, claimed and shaped by particular people at a particular moment.

Boolyglass is a small rural townland, and beyond its name and county, the surviving record for this site is thin. What can be said with confidence is that ringforts of this type were in active use roughly between the sixth and twelfth centuries, functioning as the farmsteads of free farming families and, in grander examples, of local lords. The enclosing bank served less as a serious military defence and more as a boundary marker and a means of keeping livestock in or predators out. Over the centuries, many of these monuments were levelled for agriculture, which makes those that survive, even in reduced form, worth noting.