The bank, barely 0.7 metres high and running in a circle roughly 30 metres across, is heavily overgrown, its interior swallowed by vegetation. It is, on the surface, an unremarkable hump in a field. What makes it worth pausing over is its age and its ordinariness in equal measure: this is a rath, an early medieval farmstead enclosure of a type once so common across Ireland that an estimated 40,000 or more survive in various states of preservation.

Raths, sometimes called ringforts, were the typical settlements of farming families in early medieval Ireland, broadly spanning the period from around the fifth to the twelfth centuries. The earthen bank, thrown up from a central ditch, defined a domestic space: somewhere to keep livestock safe at night, to build a house or two, to live out a life largely unrecorded by history. The one at Toom follows that familiar form, its circular plan a practical rather than ceremonial choice, and its position on a break in the slope suggesting the usual concerns of early farmers, drainage, shelter, and a reasonable view of the surrounding land. The Blackwater valley would have offered fertile ground, and it is likely that whoever raised this bank was working land not very different from what surrounds it today.