At the northern tip of a narrow, steep-sided ridge on the landscaped grounds of Furness House in County Kildare, a large prehistoric enclosure sits quietly in pasture, its circular earthen bank enclosing a space 63 metres across. What makes it quietly arresting is what stands at its centre: a fine upright standing stone, the kind of solitary megalith that tends to draw the eye long before you fully understand what surrounds it. The bank itself, between six and eight metres wide and averaging two metres in height, is interrupted by two entrance gaps positioned on roughly opposing sides, facing ENE and W. An outer fosse, a defensive or boundary ditch, runs around the perimeter, and faint traces of a second outer bank were still discernible when the site was examined in 1972. About 65 metres to the south-east, a small burial cairn adds another layer to what is clearly a concentrated prehistoric landscape.

Beside the standing stone, a cist was discovered, a small stone-lined burial box of the kind typically associated with the Bronze Age, suggesting the enclosure had a ceremonial or funerary function rather than a purely practical one. This combination of enclosure, standing stone, and cist is not unique to Forenaghts Great. County Kildare preserves comparable groupings at Punchestown and Mullaghmast, pointing to a broader regional pattern in how prehistoric communities marked and used elevated ground. The site has been in the scholarly record since at least the late nineteenth century, with references appearing from 1896 onward, and it attracted detailed attention from Macalister, Praeger, and Armstrong in a publication from 1912 to 1914. A 2006 aerial photograph showed the enclosing bank partially stripped of sod, apparently by grazing livestock, a reminder that even protected monuments are not immune to the ordinary pressures of agricultural land.

The monument carries a Preservation Order, one of the earlier such designations applied under Irish national monuments legislation, which reflects how long it has been recognised as significant. It sits within the grounds of Furness House, meaning access is not straightforward for casual visitors, but the enclosure is substantial enough that its profile is readable from a distance across the ridge.