The tomb, recorded as a dolmen enclosed within a circle of standing stones, is gone. What replaced it is still there, which makes this patch of south Dublin coastline a place where one absence tells you rather more than most presences would.

A dolmen is one of the oldest and most recognisable forms of megalithic architecture: a large capstone raised on upright supports to create a chamber, typically dating to the Neolithic period. This particular example was surrounded by a stone circle, a combination that suggests a site of some ceremonial or funerary significance. Liam Price noted the arrangement in 1940, drawing on earlier descriptions, but by then the tomb had already been gone for well over a century. According to Samuel Lewis, writing in 1837, it was destroyed during the construction of a martello tower in the eighteenth century. Martello towers were low, thick-walled circular fortifications built along the Irish and British coastlines during the Napoleonic era, intended as a defence against potential French invasion. The one at Dalkey Commons was, in effect, built on top of, or out of, something several thousand years older.

Dalkey Commons is a public open space and the martello tower is visible enough, sitting near the coast south of the town. There is no marker or interpretation panel noting what was lost here, as far as records suggest, so visitors are largely left to make their own imaginative reconstruction. The tower itself is the main physical reference point. It is worth pausing to consider the scale of what the builders displaced: a megalithic monument substantial enough to have a surrounding stone circle would have been a landmark in its own right long before the coastline became militarised. The commons are accessible on foot from Dalkey village, and the broader area repays a slow walk, though the tomb itself exists now only in the bibliographic record.