Measuring roughly 72 metres along its longer north-northeast to south-southwest axis and only 25 metres across, the enclosure is far narrower in proportion than most examples of its kind, which gives it an almost corridor-like quality when viewed from above.

The site is defined partly by a constructed earthen bank running from the north around through the east to the south-southeast, and partly by a natural scarp, where the ground simply drops away and does the work of enclosure on its own. An entrance gap survives at the north-northeast. A later field boundary has been laid directly over the bank along the southern arc, the kind of quiet overwriting that happened across rural Ireland as agricultural land was parcelled up across the centuries, slowly blurring older boundaries into newer ones. What makes the townland of Breanra particularly notable is density: this enclosure is one of four such earthwork sites recorded within the same townland, a clustering that suggests the area supported a significant, if now largely invisible, early settlement pattern. Neary noted the site as far back as 1914, which places it among the earlier formally documented earthworks in the region.