VICTORIAN boundary stones that mark the edge of Dartmoor Prison have been microchipped to prevent their theft. The bounds to the original prisoner of war prison covered an area of 390 acres, extended to 1,000 acres in 1867 when it became the convict prison. The whole area was then marked with boundary stones inscribed with DCP and an upwards pointing arrow. There were 21 stones and there was an original requirement annually to walk around the stones to ensure they were still in place. It took a day to complete, but this has not been done for many years. More than half the bound stones have now been rediscovered, with the aid of a copy of a plan of the original bounds. Some lie under tarmac or concealed under years of vegetation growth. Others are situated on the open moor. To deter theft it was decided to microchip those which had been rediscovered, which were standing near the road.