The position is not incidental. Whoever built this rath, a type of enclosed farmstead or defended settlement common in early medieval Ireland, chose a site that commanded views over a shallow sea inlet to the north and a broader one to the south, making it one of the more deliberately placed examples along this stretch of the Mayo coast.

The enclosure measures approximately 26 metres north to south and 25.5 metres east to west, defined by an earthen bank that in places still stands to about 0.85 metres in height on the western side, dropping away as a scarp of up to 2.5 metres on the northern and southern faces where the natural ridge does much of the defensive work. What makes the bank itself curious is its composition: stones protrude from it at various points, and oyster and limpet shells are worked into the fabric of the bank in parts, suggesting the people who used this place had ready access to the shoreline below. A fosse, or external ditch, was recorded along the western half of the rath during an inspection in the first half of the twentieth century, though by a 1987 inspection no trace of it remained. There is a break in the bank at the west-south-west that might mark an original entrance, though this is not certain. The rath is recorded under the name Lismore on Ordnance Survey maps dating to both 1838 and 1920, and the 1920 map also marks a chapel site within the southern half of the interior. No physical trace of that structure survives at ground level today.