To the south-south-west and west, the bank rises to an internal height of 2.1 metres and is constructed from earth alone; moving towards the north, the same bank becomes stone-faced; and continuing back around to the south-south-west, it drops to a low earthen ridge now crowned by an ordinary field fence. A shallow fosse, the external ditch that once reinforced the enclosure's defensive or symbolic boundary, survives along the south-south-west to west arc. The circuit is broken in two places, at the east-south-east and at the west, and a low mound of loose stone sits near the centre of the interior.

This is a rath, the most common monument type in the Irish landscape. Raths are ringforts built primarily from earth and sometimes stone, enclosing a roughly circular area that would have served as a defended farmstead during the early medieval period, broadly from around the fifth to the twelfth century. The Mountgabriel example measures approximately 52 metres north to south and 50 metres east to west, placing it comfortably within the typical size range for such sites. What gives this particular rath a layer of additional interest is what survives inside: cultivation ridges running on a north-south axis across the north-west quadrant of the interior. These are the faint corrugations left by lazy-bed cultivation, a method of raising crops in ridged mounds that was once widespread across Ireland. Whether these ridges belong to the early medieval occupation or to a later period of agricultural use is not recorded, but their presence on the same ground as the enclosing bank gives the site a palimpsest quality, one era of land use written faintly over another.