The mound at Tomriland sits roughly eighty yards across, rising gradually from its edges to a centre some ten feet above the surrounding ground. What caught scholarly attention early on was not just its shape but the tochar, a causeway or raised trackway, that approached it from the direction of Annamoe, suggesting deliberate construction and perhaps an original watery setting. A site that seems to announce itself as a defended enclosure carries a certain weight of implication.

The scholar Goddard Henry Orpen, writing in the Journal of the Royal Society of Antiquaries of Ireland in 1908, described it as a circular fort with a slight rampart and outer ditch, and offered the interpretation that it had probably served as a Celtic island-fortress, most likely sitting within or beside wetland. He was also careful to note that it had no connection with Castlekevin, the nearby medieval castle complex, separating it clearly from the Norman period. However, when the site was physically examined in 1989, the picture shifted considerably. Rather than a constructed earthwork, inspectors found a natural mound of gravel and sand, a glacial deposit of the kind left across the Irish midlands and east coast after the last ice age, and one that had by that point been extensively quarried. The causeway that once seemed so purposeful may have led not to a fort at all, but to a conveniently elevated natural feature that someone, at some point, found useful enough to shape or approach with intention.

What remains is genuinely ambiguous: a mound that has attracted both romantic interpretation and geological deflation, placed under a preservation order in 1989 precisely because what survives is fragile and already diminished. The preservation order, made under the National Monuments Acts, acknowledges that even a misread or partially destroyed monument carries something worth protecting.