Excavation begins at historic Lancaster Castle Hill site
A new archaeological dig has begun near Lancaster Castle with the aim of learning more about its Roman past.
The two-week Castle Hill project hopes to confirm theories it was once the site of a much bigger Roman shore fort.
A succession of forts is thought to have occupied Castle Hill between the 1st Century and 4th Century.
The excavation will partly re-open trenches dug in the late 1920s and early 1970s in the hope of understanding earlier research.
Jason Wood, the excavation director and heritage consultant to the Beyond the Castle project, said: "The dig represents an important opportunity to test our theories relating to the location of Lancaster's Late Roman Shore Fort.
"Hopefully it will enable us to consolidate our understanding of the site and what this might tell us about the nature and character of Lancaster in Roman times."
Shore forts are situated on shorelines and inland on navigable rivers. In Roman times, Mr Wood said the shoreline of Lancaster would have been slightly different.
History of Lancaster Castle
Originally a Roman fort, and sometimes known as John O'Gaunt's Castle, it stood as a bastion against the forces of the ancient Picts and Scots tribes.
The buildings include a 12th Century Norman keep, the 14th Century Witches' Tower and 15th Century Gatehouse.
The castle was the site where 10 people were convicted of witchcraft at the Summer Assize in 1612 who went to the gallows on the moors.
Among the monarchs who held court there were King John and King Henry IV.
In modern times, it was a working courtroom and witnessed the wrongful conviction of the Birmingham Six in 1975 for murders of 21 people in two pub bombings.
The Castle was also a Category C prison until 2011 and is a Grade I listed building.
Source: BBC and Lancaster Castle
Beyond the Castle is supported by the Heritage Lottery Fund and led by Lancaster City Council and Lancashire County Council.
Councillor Janice Hanson said there are "still many gaps to our knowledge" about the history of the city.
"This exciting project delving into our 'hidden depths' could potentially have a huge influence on the way we see our city and the way it has developed over the millennia."