Recovered during excavations at Bremore in north County Dublin, the object is a slate sundial of late medieval date, and what makes it particularly intriguing is the possibility that it was never finished. Whether it was discarded partway through its making, or simply lost to the ground before it could be put to use, is a question the archaeology cannot fully answer.

The sundial came to light in 2001, when archaeologist Finola O'Carroll conducted pre-development investigations under licence No. 01E0370 in advance of a large-scale housing development north of Bremore Castle. The excavation covered a large open field of approximately 4.5 hectares, with the castle lying immediately to the south and the sea just 300 metres to the east. The work exposed evidence of a medieval field system, stretches of cobbling, and two pits containing substantial quantities of late medieval pottery. The sundial itself was found in the second of these pits, adjacent to a southern ditch, along with the possible footprint of a small structure of either medieval or early post-medieval date nearby. A sundial made from slate, a material common enough in Irish medieval craft, would have been carved with hour lines radiating from a central gnomon hole; the gnomon being the projecting piece that casts the shadow used to read the time. That this example may have been unfinished places it at an unusual moment in the production process, closer to the craftsman's hand than to any wall or yard where it might eventually have served its purpose.

Bremore Castle itself sits just off the N1 road north of Balbriggan, and the eastern portion of the field examined in 2001 was set aside as parkland as part of the subsequent housing development, meaning the wider landscape around the castle remains partly accessible. The castle was noted as undergoing restoration at the time of the excavation. The sundial is no longer in situ, having been recovered as a find during the dig, but visitors to the area can still get a sense of the medieval complex and its coastal setting. For anyone wanting to examine the object more closely, a photograph is available through the Sundials of Ireland website, where M.J. Harley has documented it among examples of medieval Irish sundials.