Some 3,400 years before the A303 carriageway split the Stonehenge landscape in half, some people cut a beautiful pit a metre deep into the hard chalk using picks made of red deer antlers.
     The newly discovered pit was neatly shaped to hold a huge wooden post. A trench links to a second equally impressive pit for another massive post. In the rolling chalk downland, these would have been visible for kilometres. The line of the trench seems to lead on towards the neighbouring field, under a later bank but carefully avoiding an earlier long barrow.
     Phil McMahon, Historic England archaeologist, and Nick Seashell, of the National Trust, speculate on the feature's purpose.
     "A gateway? A boundary marker? A palisade? The truth is we just don't know," Snashall said. "We won't even have a date until we get the lab results back."
     Their survey - which includes aerial photography, ground penetrating radar, the study of old maps showing now-vanished monuments, and excavations - is assessing the route of a proposed tunnel to replace the present road. Tourists very rarely venture across the road, but thousands of monuments lie among the fields and clumps of woodland.
     Many of the known sites have never been excavated, and the survey has revealed some new ones, including a puzzling square enclosure which could be prehistoric, Roman or medieval, almost on the shoulder of the road. The survey has also shown how intensively the landscape was farmed for thousands of years: one long barrow was completely ploughed out above ground by the time the Romans arrived.
     While broad agreement about a new road plan has been reached between various government authorities, the Stonehenge Alliance - a group that includes local residents, landowners, historians, druids, and the Campaign to Protect Rural England - argue for a much longer tunnel with the entrance and exit placed well outside the world heritage site. The alliance believes that doing nothing about the present road would be much better than doing the wrong thing.

Edited from The Guardian (21 December 2015)