The water simply rose around it, leaving this round-topped earthwork stranded in the middle of a man-made body of water, with cairn material, the loose stone debris typical of prehistoric burial and ceremonial mounds, still visible around its edges.

Before the mills and their water demands reshaped the landscape, the mound sat in boggy ground that locals knew as Bog Larkin. A 19th-century account, cited by Ua Broin in 1957, described it as a "very perfect and remarkable mound nearly surrounded by a deep boggy slough," which gives some sense of how prominent it appeared even then, rising cleanly above the saturated ground. The exposed cairn material around the perimeter suggests this is likely a prehistoric monument of some kind, though the notes compiled by Geraldine Stout and Padraig Clancy do not specify a precise classification or date. Its survival, first within bog and then within a managed lake, is in itself notable.

The site sits in an area shaped by centuries of industrial use along the Clondalkin corridor, so the surrounding landscape is layered rather than purely rural. Visiting requires some attention to access, as the mound is now effectively islanded by the artificial lake, and getting a close view of the cairn material around its base may not be straightforward depending on water levels and ground conditions at the margins. The exposed stonework is the detail worth looking for, as it distinguishes this from a simple earthen mound and hints at whatever structure or deposit lies beneath.