Digging starts along River Derwent to uncover a Roman fort in Derby
Archaeologists are to start searching for a Roman fort ahead of the building of new flood defences in Derby.
The Environment Agency plans to build the £35m defences along the River Derwent at Chester Green in 2015.
However, experts believe a Roman fort exists beneath the site.
A team of contractors has been brought in by the agency and the city council. They will dig trenches and search for evidence during April and May.
Ed Wilson, the Environment Agency's senior archaeologist for the Midlands, said the dig would help establish where exactly the fort lay.
"By doing the dig at this stage, it will save us from any surprises further down the line," he said.
"We know it's the site of a Roman fort. People have dug there in the last 100 years and found a Roman bathhouse. That's still buried underground and the site is a scheduled ancient monument."
He said remains dating from Saxon and medieval times had also been found at the site.
The contractors, Oxford Archaeology, will dig 15 trenches over 10 day periods in April and May.
Mr Wilson said any major finds could lead to a complete excavation or a realignment of the flood banks.
Councillor Hardyal Dhindsa said: "We want to make sure the rich heritage is protected. I am really excited we will find artefacts, small or large, that can be added to the story of the city of Derby."
The flood defence scheme, named Our City Our River, is aimed at protecting the area which last experienced serious floods in 2007.