Most survive in upland fields or on open moorland. This one, on a coastal terrace near Sherkin Point in County Cork, is doing something rather different: it is being swallowed by the sea.

The tomb sits at the head of a narrow inlet, immediately east of Carrigdoona promontory fort, and its chamber is modest in scale, measuring roughly 2.6 metres long and just over a metre wide. One sidestone stands to the north, two to the south, and an inset backstone closes the eastern end, leaving the chamber open to the south-west in the characteristic wedge tomb manner. A low transverse stone near the western end of the southern side may represent the remains of an entrance feature or facade, and faint traces of what might once have been a covering mound are visible to the north. When the tomb was surveyed in 1988, a small hole had appeared at the north-west corner of the chamber. By 2013 and 2014, winter storms had done considerably more damage, and the entire monument had been enveloped by a rock pool that in 1988 was little more than that modest opening. The sea, in other words, has been advancing on this structure for some time, and has now largely claimed it.

The juxtaposition with Carrigdoona promontory fort next door adds a certain depth to the location. A promontory fort uses a natural headland and a constructed bank or wall to enclose a defensive or settlement site, and whoever built that fort would have had this much older tomb as a close and visible neighbour. Whether that proximity meant anything to them is unknown, but it is a reminder that prehistoric monuments were not always remote or isolated features in the landscape. They accumulated around one another, and the coastline here has been a place of human activity across a very long span of time.