Their meaning has been lost in ancient history but the distinctive marks on rocks by our ancestors thousands of years ago provide a unique link to our prehistoric past. Now a new project has been launched in an attempt to finally unravel some of the mysteries of the prehistoric rock art carved into stones in Scotland. Experts are to create a new digital database using 3D scanning to record and study more than 2,000 carvings across the country. Cup and ring marks are a form of prehistoric art found widely through out the world. They consist of a round indentation – the cup – surrounded by a series of concentric circles that look like ripples on water.