LONDON (Reuters) - Britain has given the green light to a 1.7 billion pounds tunnel under Stonehenge aimed at hiding a nearby main road that has long blighted the mysterious prehistoric circle of stones in southern England. Stonehenge, one of the world’s most famous prehistoric monuments, includes a 5,000-year-old ditch and a Neolithic stone circle with early Bronze Age burial mounds nearby. It is a World Heritage Site. Transport Secretary Grant Shapps on Thursday granted development consent for the 1.7 billion pound project which includes a new dual carriageway with a two-mile tunnel beside Stonehenge.