This is a cashel, a type of ringfort built from stone rather than earthen banks, and the one at Faunarooska is a modest but legible example of a form that once organised early medieval life across much of Ireland's rocky western landscape.

The cashel measures approximately 26.5 metres north to south and 27.5 metres east to west, making it a compact but substantial enclosure. Its defining wall has spread over time to a width of between 1.5 and 2 metres, and while much of it has collapsed into a low spread of rubble, facing stones are still occasionally visible on both the inner and outer edges, rising to between 0.25 and 0.5 metres in places. In the northern section of the wall, two gaps lined with splaying slabs, one roughly 0.6 metres wide and another about a metre across, may mark the original entrance, a common feature in cashels where upright or angled stones were used to frame and narrow a formal threshold. Near the centre of the enclosure there is a cairn, a small heap of stones whose purpose is not recorded, and a second loose spread of stones lies in the southern sector. The enclosure sits on a ridge oriented north to south and commands wide views from the north-east to the south-west, a position that would have been useful both practically and symbolically for whoever occupied it.

What makes the site worth attention is less any single dramatic feature than the layered quality of the landscape around it. The cashel sits within a multiperiod field system, meaning the boundaries, enclosures, and divisions of the land here have been reworked and reused across successive eras. The cashel is one element in that longer story, its stone walls now blending almost imperceptibly into a hillside that has been shaped and reshaped by generations of people working the same ground.