High Quality Content by WIKIPEDIA articles! The Stonehenge road tunnel was a controversial tunnel in Wiltshire, England proposed by the Highways Agency to upgrade the A303 road. It would have moved the A303 into a tunnel under the Stonehenge World Heritage Site and close the A344 road. The project was designed to improve the landscape around the monument and to improve safety on the primary A303 and was part of proposals to change the site in other ways including moving the visitors centre.