The mound at Lemonstown sits at the high point of a ridge, giving it commanding views in several directions, and while the mound itself is largely natural in origin, the earthworks surrounding it are anything but accidental. A fosse, which is a deliberately cut ditch, runs around the mound, backed by an outer earthen bank, and a second fosse lies beyond that on the southern and eastern sides. The whole arrangement stretches to a maximum diameter of 51 metres, with the mound itself rising to about 4 metres and flattening to a level platform roughly 10 metres across at its top.

The entrance is on the eastern side, where a gap in the bank aligns with a causeway crossing the inner fosse, and a ramp carries the approach across the outer ditch and berm, the narrow strip of ground between the two fosses. This kind of layered enclosure, concentric barriers of bank and ditch, suggests the site carried considerable ceremonial or social significance to the community that constructed it, though precisely when that was remains unclear from what has been recovered. The most substantial find came to light in 1818, when a bowl food vessel was unearthed on the site. Bowl food vessels are a type of ceramic associated with Early Bronze Age funerary practice in Ireland and Britain, typically dating to somewhere in the second millennium BC. That vessel, catalogued as NMI 1898-3, was recorded by Price and Walshe in 1933, and it remains the principal artefactual evidence connecting this monument to a burial tradition rather than some other purpose.