France, April 7 -- France's National Institute for Preventive Archaeological Research (Inrap) says it has unearthed the remains of a medieval castle in Vannes, on the coast of Brittany. Unexpected discoveries have allowed archaeologists to sketch out the 600-year-old structure and its internal life for the first time.

Inrap saysit carried out the dig - commissioned by the Vannes city council - early last year to check for remains before the 18th-century building on site underwent construction to become a fine arts museum.

Digging in the manor's courtyard and cellars, archaeologists found an outer wall and moat, Inrap announced last week. They also excavatedevidence of a bridge over the moat and a mill within the castle's residential are...