A proposed road tunnel past Stonehenge should be made longer with better designed entrances, the Council for British Archaeology (CBA) has said.
The government has unveiled plans for a 1.8-mile (2.9km) tunnel past the World Heritage Site.
It said this would transform the A303, cutting congestion and improving journey times.
The CBA said it backed the tunnel but lengthening it could help avoid damaging key views of the monument.
CBA director Mike Hepworth said he was keen to engage with Highways England to find a solution as the proposed western tunnel entrance was close to some significant burial sites.
"Just moving the western end by three or four hundred metres would make a huge difference to not damaging the key views and relationships which are important to understanding the landscape," he said.
"This is one of the most significant monuments in the world and we have a responsibility to maintain it for future generations."
The busy A303 in Wiltshire currently passes within a few hundred metres of the prehistoric monument.
The tunnel forms part of a £2bn government scheme to upgrade all remaining sections of the road between the M3 and M5.
A public consultation of the tunnel plan runs until 5 March.