The 18-tonne stone, measuring nearly three metres at its longest point, had been flagged for investigation by Aegis Archaeology following earlier testing in the area. Though the boulder sat just outside the construction zone, the team wanted to ensure nearby work wouldn’t cause any damage. When they lifted the massive capstone, they discovered it had been concealing a deliberately constructed megalithic chamber, likely dating back thousands of years.

The structure revealed beneath consisted of two distinct spaces: an outer chamber formed by six recumbent stones, some natural and others carefully positioned, and an inner chamber with more elaborate construction. The inner space featured a penannular (nearly circular) arrangement of stones set into the ground, bounded on one side by drystone walling built two to three courses high. A single standing stone, or orthostat, marked the northern edge of this inner chamber. The entire complex sat within a roughly oval configuration that seemed designed primarily to support the massive capstone rather than to define a specific ritual space.

Perhaps most intriguing was the evidence found on the exposed bedrock to the east of the structure. The rock face showed clear signs of quarrying, including a vertical cut that dropped to a horizontal surface, creating a perpendicular scarp unlikely to have been formed by natural glaciation. This suggests the enormous capstone may have been quarried from this very spot before being positioned over the chamber. The discovery, recorded under excavation licence 04E1397 by Archaeological Consultancy Services Ltd, offers a fascinating glimpse into the engineering capabilities and construction methods of Ireland’s prehistoric builders, who managed to manoeuvre and position these massive stones with remarkable precision.