Tregiffian burial chamber capstone cup mark

This is a large, 25cm cup mark on top of the capstone at Tregiffian burial chamber. It often fills with rain water and is easy to spot. There is a cup mark of similar size directly below on the underside of the capstone. It is thought that this may represent an attempt to cut a hole through the stone, perhaps before its use as a capstone. There are several examples of 'holed stones' in West Penwith. However, the holes do not align perfectly if the intention was to continue cutting a hole perpendicular to the surface. There would have been about a 40% overlap. Perhaps this was realised, ending up with the stone being used for another purpose - the large capstone of this burial chamber. [Explore Tregiffian burial chamber in 3D](https://sketchfab.com/3d-models/tregiffian-burial-chamber-cornwall-uk-1b6d39159c844ea5b24d869508fa3fd9) and discover more of its cup marks. *The project was funded by a British Academy/Leverhulme small research grant.* Source: Objaverse 1.0 / Sketchfab