The earthwork at Gortmore sits on low-lying, waterlogged ground in County Westmeath, roughly 45 metres west of the River Dungolman, which traces the townland boundary with Calliaghstown. It takes the rough form of a rath, the Irish term for a circular or sub-circular enclosure defined by an earthen bank, typically dating to the early medieval period and associated with farming settlements. This one measures approximately 45 metres north to south and 48 metres east to west, with its earthen bank running from south around to the north-northeast. But here the straightforward story starts to unravel.

The monument was never marked as an antiquity on any edition of the Ordnance Survey six-inch map, which is unusual for a feature of this apparent scale and form. The 1837 OS Fair Plan shows it as a tree-filled enclosure, and the 1838 six-inch edition records it as a plantation rather than an archaeological site. By the revised 1914 edition, it had been redrawn as an ordinary polygonal field. The interior rises naturally in the eastern quadrant, forming a round hump inside the bank, and the eastern and southeastern edges are now defined by field fences rather than any original earthwork. All of this points to a site that has been significantly modified or landscaped at some point in the past, possibly not a ringfort at all in origin, but rather a designed landscape feature, perhaps a tree plantation laid out in connection with Longfield House, which stands about 560 metres to the south. Whether the earthen bank preserves something genuinely ancient beneath later reshaping, or whether the whole thing began as a Georgian garden conceit on soggy midland ground, remains an open question.