A circular mound of stone, roughly 18 metres across and standing 2.3 metres above the lake-bed, sits in quiet isolation, its edges spilling stones into the water around it, its plateau lightly grassed over and tangled with briars. This is a crannog, an artificial island of the kind built across Ireland and Scotland from the Bronze Age onwards, typically by piling up timber, stone, brush, and peat to create a defensible or secluded dwelling place in a lake. What makes the Lough Talt example particularly legible, even from a distance, is its form: a high-cairn type, built largely of stone rather than organic material, with a distinct central plateau and a berm stepping down around three sides of it.

The internal detail is considerable for a site so overgrown. The central plateau rests on a firmer layer of shattered and fire-cracked stones, suggesting sustained habitation and the repeated lighting of fires. On the eastern half of the plateau, a cluster of boulders may be the remnant of a wall. To the west, a jetty of small stones extends outward across the water, and on the northern side of the jetty a submerged flagstone path runs for nearly five metres, just below the surface. This was not simply a pile of rubble but a structured, engineered place, with an approach, a threshold, and interior spaces. The antiquarian W. G. Wood-Martin, writing in 1892, recorded finds from the crannog that included a bone arrowhead, polished and worked bone fragments, a wooden beam, and the teeth and bones of oxen, sheep, and horses, the ordinary debris of a working settlement. A second, possible crannog lies roughly 1.2 kilometres to the south-south-east, near the southern end of the same lough, suggesting this stretch of water supported more than one such community at some point in the past.

Lough Talt sits in a mountain valley in south Sligo, and the surrounding terrain closes off long views, giving the lake an enclosed, self-contained quality. The crannog is visible from the shoreline, though the water between is not fordable, and the site itself, overgrown and unreachable without a boat, retains a degree of remove that is, in its way, entirely appropriate to what it once was.