Archaeologists are unearthing the remains of a Roman bridge.
The ruins of the bridge, which would have once crossed the River Tyne, have been undisturbed for thousands of years in Corbridge, Northumberland.
The site has been monitored since the 1970s by archaeologists concerned at erosion of the remains by the river.
In 1995 a trial excavation revealed the rapid rate and severity of the damage caused by erosion, which has increased in recent years.
It is thought the bridge probably collapsed because of river erosion during the Anglo-Saxon period.
Tyne and Wear Museums' archaeology team, with the help of volunteers and trainees, started work on the excavation two weeks ago.
The team has already uncovered the spectacular scale and decoration of the bridge, which would have carried the main Roman road from London to Scotland.
Tyne and Wear Museums keeper of archaeology Margaret Snape said: "This is a very exciting project giving us the opportunity to uncover and display a spectacular example of Roman architecture and engineering.
"We have already made some fascinating discoveries and welcome people to come along and watch us at work."
The work is taking place on the south bank of the river where a huge causeway would have carried the road, known as Dere Street, from the flood plain on to the bridge at a height of 26ft (8m) above the river.
An information tent is due to be set up during the dig so visitors can find out the latest news and will have the chance to handle finds.