At its peak, the group numbered at least 245 stones, according to a survey published in the Archaeological Survey of Ikerrin (Stout, 1984). By 1936, when the Inspector of National Monuments mapped and catalogued what remained, 221 were still accounted for, spread across the two townlands, with 173 in Timoney Hills and 48 in the adjoining Cullaun. The inspector noted that the stones, all of red sandstone or conglomerate, stood or had once stood between roughly 0.9 and 1.8 metres above ground. They appear, as he put it, to follow no particular arrangement or system, with one exception: a single stone circle in Cullaun that stands apart from the rest.

The sheer number of stones, and the fact that they sit within the landscaped grounds of the Parker-Hutchinson estate at Timoney Park, has been enough to cast genuine doubt on whether they are prehistoric at all. It is possible that some or all were placed during the improvement and ornamentation of a private demesne, a common enough practice among landed estates in the eighteenth and nineteenth centuries, where megalithic-looking arrangements were sometimes constructed as romantic or antiquarian features. By 1984, seventy stones had been removed entirely, and five cairns that appeared on earlier maps were also gone. One stone catalogued by the 1934 to 1936 survey as number 6C, within a field where twelve stones were upright and twenty-three lay prostrate, could not even be located by later surveyors due to dense scrub growth. Whether the group is genuinely ancient, partly ancient, or a landlord's folly, the uncertainty itself is part of what makes Timoney Hills quietly compelling.