Carved Stone Balls are Petrospheres, usually round and rarely oval. They have protruding knobs on the surface, from 3 to 160 in number. Their size is fairly uniform, they date from the late Neolithic to possibly the Iron Age and are mainly found in Scotland. They range from no ornamentation (apart from the knobs) to extensive and highly varied engravings.
They are around 4000 years old, coming from the late Neolithic and bronze age, with a possibility that they were still used in the Iron Age. All but five have been found in Scotland, the majority between the River Tay and the Moray Firth, these lands being the highly fertile lands lying to the east of the Grampian Mountains. A similar distribution to that of Pictish symbols has led to the suggestion that Carved Stone Balls are Pictish artefacts.