They sit in loose arrangement around a ringfort, one of those circular earthwork enclosures associated broadly with early medieval settlement in Ireland, and together they suggest a small community that left almost no record beyond the shapes pressed into the earth beneath the grass.

The three structures differ enough in form to raise quiet questions about their relationship to one another and to the fort nearby. The first is a circular house, roughly 2.8 metres in diameter, located about 50 metres to the south-east of the ringfort. Poorly preserved, it survives as a grassed-over stone wall running from south through west to north-north-east, with faint traces of inner and outer wall-facing still legible. Immediately adjoining it on its west-south-west side is a second, subcircular structure, slightly larger at 3 metres by 2.5 metres, built in a similar fashion. Whether the two were contemporary, or whether one was added against the other at a later point, is not recorded. The third house is the most distinct: a rectangular building, 10 metres long and 3.6 metres wide, oriented east to west, constructed from a double-faced wall of limestone blocks, and sitting about 11 metres to the north of the ringfort. The shift from circular to rectangular plan is archaeologically significant in Ireland, generally associated with a transition from early medieval to later settlement forms, though at Tomnahulla no date has been assigned to any of the three.

What remains visible today is modest by any measure: grassed-over outlines, a few limestone courses, the suggestion of walls rather than walls themselves. The site does not announce itself, and that is part of what makes it worth attention. The density of features in a small area, three house types clustered around a ringfort of uncertain period, gives the place an unresolved quality that no amount of tidying up could improve.