What they tend to walk past, without noticing, is a far quieter structure just 75 metres to the south, a low oval mound barely a quarter of a metre high, its grass-covered surface giving almost nothing away.

The mound measures roughly 4.5 metres north to south and 4 metres east to west, and appears to be composed primarily of fragmentary limestone. A barely discernible fosse, the shallow encircling ditch that sometimes defines the perimeter of prehistoric monuments, traces its outer edge. What makes the site quietly compelling is a single block of white quartzite, measuring approximately 35 by 15 centimetres, placed on the eastern perimeter. Quartzite does not occur naturally on Knocknarea. Someone brought it here deliberately. The archaeologist Stefan Bergh, writing in 1995, recorded this detail alongside several other monuments clustered on and around the summit, including a possible passage tomb just 8 metres to the north-north-east and a further cairn 26 metres to the south-east. The summit of Knocknarea was, it seems, a place that accumulated monuments over time, each new structure orientating itself in relation to what already existed. Whether this particular mound is itself a passage tomb, a simpler cairn, or something else entirely remains uncertain. The classification is tentative, and the ground gives up very little at a glance.

The mound sits within a dense constellation of prehistoric remains on the summit plateau, all of them in the shadow of Maeve's Cairn. Reaching it requires the same approach as the main monument, a well-used path from the car park at Knocknarea. Once at the top, it rewards a slower kind of attention than the great cairn demands, the kind that notices a placed stone, a faint dip in the turf, and begins to ask questions the landscape does not immediately answer.