By Susie Beever & Chris Matthews An iconic landmark in Cornwall has caused mysterious vibes after it was decorated with some rather X-rated items. Often dubbed the county’s own ‘Great Wall of China’, the wall running along the road between Falmouth and Truro is well known among motorists and locals for being festooned with mugs. The reason why – and indeed the person behind the stunt – has long been unknown. But the bizarre charade took an explicit turn over the New Year, when the cups were replaced with objects not usually found in a kitchen cupboard. Drivers were stunned to notice a row of d…