More than 500 of these 5,000-year-old carved stone balls have been discovered, mostly in Scotland, but their purpose remains a mystery.
Featuring knobs and intricate markings of spirals and lines, these stone balls date back to around 3,200 BC to 2,500 BC.
The Towie ball, seen here as a 3D image, is perhaps the most beautiful example. It is on display at the National Museums Scotland, in Edinburgh.
Some of the balls were found in the remarkably preserved Neolithic settlement of Skara Brae, in the Orkney Islands, off the northern coast of Scotland.
The carved stone balls were created during an era when people transitioned from hunter gatherers to farmers, in settlements such as Skara Brae.
To gain a better understanding of the carved stone balls, and to bring the collection closer to the public, Hugo Anderson-Whymark, curator of National Museums Scotland, created 3D images of 60 balls from the museum's collection.
Using a technique called photogrammetry, Anderson-Whymark took hundreds of 2D images from every angle to create very detailed 3D renderings of the stone balls. The resulting 3D images revealed previously unseen details in the design.
For instance, this 3D image of a carved stone ball from Buchromb, Banffshire, showed evidence that the large knob was reworked into smaller ones over time, suggesting a process of modification that was not known before the 3D images were made.