On the summit of Laghtnafrankee Mountain in the Glendalough valley of County Waterford, a modest heap of stones sits doing double duty across several thousand years of history. A prehistoric cairn, roughly 8.7 metres east to west and 7 metres north to south but only 0.6 metres high, now serves as the base for a trigonometric station, one of the concrete or metal survey markers used by Ordnance Survey teams to calculate precise ground positions across the landscape. The arrangement is quietly odd: a structure raised by people who presumably gathered the stones with ceremony or communal effort, now pressed into service as a platform for modern cartography.

Cairns of this kind are among the more common prehistoric monuments on Irish uplands, typically constructed during the Neolithic or Bronze Age as burial monuments or territorial markers, sometimes both. They were usually built from locally gathered stone, occasionally edged with kerbstones to define the mound's perimeter. This one has no visible kerbstones and no other surviving features to hint at what, if anything, lies beneath. The name Laghtnafrankee is itself suggestive: "lacht" or "leacht" in Irish place names often refers to a burial cairn or monument, which may indicate a long local memory of the site's funerary associations, though the specific meaning of the full name is not recorded here.