Bonhard Castle was an L-plan tower house, dating from the 16th century, around 1.5 miles (2.4 km) south east of Bo'ness, in West Lothian, Scotland.
[3] Alternative names were Bonhard House, and Polkmyl Tower.
It was subdivided into farm-servant's dwellings, and altered internally.
[3] The tower, which stood in a commanding position, had three storeys and a garret, with a semi-octagonal stair tower in the re-entrant angle.
The original doorway was at the foot of the stair tower.