These accumulations can look unremarkable from above, little more than a pale scatter in the soil, but they preserve evidence of human behaviour stretching back thousands of years.

A single oyster shell recovered from this particular midden was submitted for radiocarbon dating and returned a determination of 3400 plus or minus 50 BP, which calibrates to a date range of roughly 1940 to 1630 BC. That places the deposit firmly in the Bronze Age, a period when communities along Ireland's Atlantic coast were working copper and bronze, raising monuments, and clearly, gathering oysters in the tidal shallows near Culleenduff. The laboratory reference for the date is Beta 155380, and the result was published by Milner and Woodman in 2007. A single dated shell is a narrow window, but it is a precise one, and it fixes a moment of ordinary coastal life to a span of three centuries more than three and a half millennia ago.