Archaeologists are to excavate what they think could be the site of a Roman lead mine dating back at least 1,600 years.
The Roman site was discovered underneath the medieval track
In June last year, Cambria Archaeology unearthed the best preserved example of a medieval track in Wales in a peat bog near Borth in Ceredigion.
But workers also stumbled across evidence of what they described as a Roman "industrial estate."
Next month they are going back to the village to probe the area again.
Cambria Archaeology, from Llandeilo, intends to find out the date of the site, what was happening there and who was working it.
Students from the University of Birmingham, who helped last year, have agreed to return as have specialists from Lampeter University.
The dig at Llancynfelyn, near Borth, will begin on 31 May and end on 17 June.
Cambria Archaeology director Gwilym Hughes said: "We have found debris to the south of the track which could date back to Roman times.
"We know there were lead mines in the area so there could have been a Roman mine there."
Mr Hughes said the reason for building a timber track across a peat bog had baffled experts.
"We don't know the date of the industrial origins, but it could be earlier than the medieval track," he added.
"I suspect the track had something to do with the mine."
"It's very exciting because we have the potential of finding out why the Romans thought this site was important."
Last year the team said the medieval track was made up of thick wooden beams and had been protected by a peat bog which had covered it for centuries.
Carbon dating carried out on fragments of wood from the site date back to 900 or 1020AD.
The trackway was on edge of Cors Fochno (Borth Bog). This is an area of wetland containing both tidal and freshwater marshes and it is a site of great ecological importance.
An open day is planned at the site. Directions and more details of the event will be posted on Cambria Archaeology's website.