Three metal detector fans have discovered a Roman hoard worth tens of thousands of pounds while spending the weekend camping in south-west England.The group were staying in a field near the ancient village of Pewsey, in Wiltshire, when they found the treasure trove a mere six paces from where they had pitched their tent.Robert Abbott, 53, switched on his device after breakfast one morning and very quickly found something.At first the computer shop owner from Essex, near London, uncovered only discarded metal tent pegs. But he dug a little deeper and hidden below was a valuable silver Roman coin called...