Pictish carving, Trusty's Hill

The top of this bracken-covered hill is surrounded by the tumbled walls of a once massive stone rampart. To the north east is a huge rock-cut ditch. These defenses may be late prehistoric but excavation has shown that the whole hill was re-fortified as a British stronghold during the 5th or 6th century. The fort was destroyed by fire in the 7th century, perhaps during attack by the advancing Northumbrians.   On a rock outcrop close to the fort's entrance is a strange carving, now protected by an iron cage. The design includes a z-shape with two discs, an abstract animal and a human head. These are typical Pictish symbols and this is the only known example of Pictish carving in south-west Scotland. Why was this carving made so far from the Pictish heartland? Does it commemorate a successful raid by Pictish warriors?