Over 200 carved stone balls have been found in Scotland, the size of oranges and each distinctively decorated. They were made in the Neolithic, and no one knows why.
After a new study of these puzzling objects, Hugo Anderson-Whymark asks how they might have been used.
The vast majority have been found, by chance, as dislocated finds across Britain, but with an apparent concentration in north-east Scotland.
The Ness ball was found under the north-east buttress of Structure Ten, one of a series of special deposits, under the building’s buttresses, that suggest they were perhaps foundation deposits for the entire building.