This charming Federal period dwelling in Mansfield, Massachusetts, was built around 1830 by Solomon Pratt and his brother-in-law, Elkanah Bates as a boarding house for the workers at their nearby cotton mill. The duplex was historically split down the middle with a unit on each side, accessed by the shared center stairhall. Local lore states that the Irish immigrant families who lived in this property reported that there were “supernatural” noises in the house, which frightened the occupants, they would tell friends it was “thundering in the castle”, giving the property the nickname, Thunder Castle.