The monument at Lettereeneen sits on the lower south-east-facing slopes of the Partry Mountains, in rough pasture of rushes, sedges and upland grasses, with wide views across the western shores of Lough Mask and the ridgeline of Maumtrasna Mountain filling the southern horizon. The stones are so low and unobtrusive that even an observer standing close by might not register them as anything deliberate.

The row stretches just 3.8 metres from end to end and follows a north-north-east to south-south-west alignment. All three stones appear to be gneiss, a coarse-grained metamorphic rock common to the area. The two outermost stones are upright and set firm in the ground, their long axes running with the row; the south-western stone is roughly oval in cross-section, while the north-eastern is flatter and more sub-rectangular. Between them, the middle stone lies prostrate in a slight hollow, angled differently from the others and noticeably more angular and sharp-edged in form. Whether it was always recumbent, or whether it once stood upright, is not known. About 4.8 metres to the south lies a cairn, and 300 metres to the north-east, on a higher elevation, there is another stone row accompanied by a ringbarrow, a type of low circular earthwork associated with Bronze Age burial practice. The concentration of monuments on this hillside suggests deliberate, repeated use of the landscape over a long period.

The site was first brought to wider attention in 1999, when Michael O'Sullivan of Dooroy, Clonbur, in County Galway, led Eamon Cody of the National Museum of Ireland to the spot. Cody had no Ordnance Survey maps to hand that day, so a precise location could not be fixed at the time. The exact position was only formally established in 2017, meaning this small cluster of ancient stones spent nearly two decades known but unanchored on any map.