On a narrow, cliff-edged terrace on the south-western slope of Grange Hill in County Kildare, there sits an earthen mound with a name that carries a good deal of local weight. Known as the Chair of Kildare, the site commands the pass between Grange Hill, which rises to 743 feet above sea level, and the neighbouring Dunmurry Hill at 769 feet. The name alone raises questions. Not a throne room, not a cathedral seat, but a grass-covered mound on a hillside terrace, associated in local tradition with the Earls of Kildare, one of the most powerful dynasties in medieval Ireland.

The mound itself is circular in plan, steep-sided and flat-topped, measuring 21 metres across at the base and narrowing to 9 metres at the summit. It rises between 2 and 5.5 metres depending on which side you approach, the south-eastern face being considerably higher. On the south-western surface of the mound there is a shallow, square depression, roughly 4 metres by 4 metres and about 0.6 metres deep, which may represent the footprint of a small castle. A motte, as this type of earthen mound is known, was a standard component of early medieval fortification, typically supporting a timber or stone tower and forming part of what is called a motte and bailey castle. Whether that interpretation holds here, or whether the depression is something else entirely, remains uncertain. Abutting the mound to the south-west is a lower, sub-rectangular enclosure approximately 28 metres by 26 metres, defined by a low scarp and partly retained by a grassed-over stone wall. A townland boundary wall cuts across the north-western portion of the monument, suggesting the site has been absorbed into the working landscape over the centuries without being entirely forgotten.

The monument is partly overgrown but described as fairly well preserved. Its position on the terrace, overlooking the narrow gap between two hills, gives some sense of why someone chose this spot, whether for defence, for ceremony, or simply to be seen.