Plans to put the major road past Stonehenge into a tunnel more than 3km long have been hailed as a momentous decision for the heritage site.
Ministers have announced moves to tackle congestion on the A303 as it passes the World Heritage Site – a notorious bottleneck on a major route to the South West – including putting the road into a 2.9km dual carriageway tunnel past the landmark stones.
The STG2 billion ($A3.65 billion) scheme was welcomed by English Heritage, which looks after the stone circle, and the National Trust, which owns much of the land in the wider World Heritage Site.
Although the stones will no longer be visible to motorists driving past, the tunnel will reconnect Stonehenge with two-thirds of the World Heritage Site that lie to the south of the A303 and are currently cut off by it.
The heritage groups said the tunnel would make the setting of the stones more tranquil, give the public greater access to the wider prehistoric landscape and improve the environment for wildlife.
It is the latest attempt to improve the setting of Stonehenge, one of the UK's most famous heritage sites with more than a million visitors a year, in a saga that has rumbled on since it became a World Heritage Site three decades ago.
A 2.1km tunnel was proposed a decade ago, but the plan was abandoned amid spiralling costs in 2007. Last year, the A344 just past the stones was closed and facilities relocated to a new visitors' centre some 2.4km away.
Officials attempted to resurrect the 2km tunnel as an option for tackling the A303 bottleneck earlier this year, but English Heritage and the National Trust rejected the plans as "unacceptable".
They proposed longer tunnel options which would take the road out of more of the World Heritage Site, reduce the impact of the tunnel's exits and entrances and move them further away from ancient burial sites, or barrows, which dot the landscape.
