For almost a century archaeologists have been braving the wind and rain on an exposed Welsh hillside in an attempt to solve one of the key mysteries of Stonehenge.
But new research about to be published suggests that over the decades they may have been chipping away at the wrong rocky outcrop on thePreseli Hills in Pembrokeshire.
The work in the hills is a crucial element in the understanding ofStonehenge because it is generally accepted that the bluestones that form part of the ancient Wiltshire monument came from this remote spot in south-west Wales. One of the many huge puzzles remains how the bluestone from Wales travelled 190 miles to the heart of south-west England.