Located on a rocky promontory beyond the village of Blackness, Blackness Castle stands on the south shore of the Firth of Forth 3 miles (5 km) east of Bo'ness. It was built as a place of defence around 1440 by the Crichton family. By 1453 ownership had passed to the Crown, Sir George Crichton (brother of Sir William, Chancellor of Scotland) having presented it to King James II (1430-60). Its occupants traditionally became the Lord High Admirals of the Forth. Between 1537 and 1543 the castle was reinforced by Sir James Hamilton of Finnart (d.1540) to become one of the strongest fortifications in Scotland. It was at this time that the castle took the form of a ship, with the bow pointing out to the river and the stern facing inland. Blackness was used as a high-security prison until 1707, its most famous prisoner being Cardinal David Beaton (1494 - 1548). It was besieged and severely damaged by Oliver Cromwell's army in 1650, and was subsequently repaired to confine the Covenanters in 1667. After 50 years of obscurity, it was pressed into service once again to hold French prisoners during the Napoleonic Wars until 1815.
The castle comprises three towers, the Central Tower rising to four storeys, the South Tower where the principal residential rooms were located, and the North Tower where the prison and pit were to be found.
In 1870, the castle was converted once again to become the principal ammunition depot for Scotland. Separate barrack blocks for the officers and men were constructed along with a new seaward entrance and a long pier extending out into the deep water of the river.
Blackness which was acquired by the Ministry of Works in 1912 was briefly reused as a military installation during the First World War. It was refurbished during the 1920s to remove the more modern buildings within its walls and to restore its appearance as a mediaeval castle. Today it is in the care of Historic Scotland and has been used as a film location for productions of Hamlet and Ivanhoe. It attracted almost 16,000 visitors in 2012.