Known as Rathmore, a name recorded on the 1837 Ordnance Survey Fair Plan map where it was shown as a circular enclosure with trees along its perimeter, the site began life as a ringfort, the kind of enclosed farmstead that tens of thousands of Irish families occupied during the early medieval period, typically comprising a circular area bounded by an earthen bank and ditch. What makes this one a little stranger is the strong possibility that, sometime after 1700, the old enclosure was deliberately reused as a tree ring, a landscaping feature associated with demesne estates of the post-medieval period, in which ornamental or sheltering trees were planted within a pre-existing or newly formed circular boundary.

The monument today is not quite the neat circle suggested by the old map. The present remains form an elongated oval, roughly 33 metres across on its longer NNW-SSE axis and about 19 metres on the shorter ENE-WSW axis, enclosed by a fragmentary earthen bank. A possible entrance gap just over a metre wide is visible at the NNW. Inside the eastern quadrant, four large stone slabs survive; two are set on edge side by side, one lies flat, and the fourth rests against it. A fifth grass-covered slab sits further towards the centre. Several tree trunks remain in the interior, consistent with the tree-ring reuse theory. A large depression on the ESE side of the monument is likely the result of quarrying, which would also explain the gravel pit recorded outside the bank to the southeast on the 1837 map. Conlanstown House, the probable seat of whoever redesigned the site in the post-medieval period, stands approximately 445 metres to the northwest.