LONDON— British authorities on Tuesday approved plans for a contentious and long-delayed road tunnel under the site of Stonehenge – but altered its route so it won’t impede views of the sun during the winter solstice.

The government said the 1.8-mile tunnel will bury a frequently gridlocked road that now runs past the prehistoric monument in southwest England.

The tunnel will “reconnect the two halves of the 6,500-acre World Heritage site, which is currently split by the road, and remove the sight and sound of traffic from the Stonehenge landscape,” Britain’s Department for Transport said.

The sun rises as thousands of revellers gather at the ancient stone circle Stonehenge to celebrate the Summer Solstice, the longest day of the year, near Salisbury, England on June 21, 2015. Associated Press/Tim Ireland

It said the revised route will be 50 yards farther from the giant stone circle than previously proposed “to avoid conflicting with the solstice alignment.”

But critics say the tunnel will disturb a rich archaeological site. Tony Robinson, host of the TV archaeology show “Time Team,” accused the government of “driving a thousand coaches and horses through the World Heritage Site.”

University of Buckingham archaeologist David Jacques said “the Stonehenge landscape is unutterably precious and you tamper with it at your peril.”

Conservationists, including the United Nations heritage body UNESCO, say diverting the road with a bypass would be a less disruptive option.

Stonehenge, built between 3000 B.C. and 1600 B.C. is one of Britain’s most popular tourist attractions.