The cashel at Moarhaun, in County Clare, is sub-triangular, with a straight eastern side and an acute angle pinched into its south-western corner, giving the enclosure a geometry that feels more deliberate than accidental. A cashel is simply a ringfort defined by a stone wall rather than an earthen bank and ditch, and this one sits on a gentle rise on the floor of an east-west valley, modest in elevation but positioned to make the most of its surroundings.

The interior of the enclosure measures roughly 26.5 metres east to west and 22.4 metres north to south. The boundary wall survives in varying condition around the circuit. Along the western and northern stretches it stands as a drystone wall, a construction technique using no mortar, around 0.6 metres wide, with an external height of 1.2 metres. At the north the wall has spread into a rubble mass approximately three metres wide and 1.7 metres high on the outside. Along the northern to south-eastern arc the wall has been rebuilt at some point, though it is now heavily overgrown, running to about two metres wide and one metre high. At the south, accumulated spoil obscures the structure entirely. Two entrances break the circuit, both modern in origin, one at the east-south-east and one at the north-east. It is at this north-eastern gap that the original fabric is most legible, where the wall can be seen to have been 1.8 metres wide, with the original facing stones still in place on either side.

The north-eastern entrance is worth pausing at. Those facing stones, set carefully at the threshold of a structure that is otherwise patched, collapsed, or buried in places, give a clearer sense of the original construction than anything else visible at the site. The grass and scrub covering the interior make the interior dimensions difficult to read from inside, but the outer wall height, particularly along the northern spread, conveys the scale of what was built here.