Visitors to Stonehenge will no longer have to shut out the sound of thundering traffic as they admire the ancient monument.

The 1.8-mile (2.9-kilometer) tunnel, part of a 2 billion pound ($3.2 billion) upgrade to the road, will eliminate motorists' view of the stone circle. But Helen Ghosh, director of heritage group the National Trust, said visitors to the site "will once again be able to hear the sounds of skylarks singing rather than the constant noise of traffic."

Stonehenge, built by Neolithic Britons between 3000 B.C. and 1600 B.C. is visited by a million people a year.

A second road was closed last year as part of a makeover designed to de-clutter the surrounding landscape.

The tunnel is among 80 new road projects announced Monday by the British government.