Ravenscraig Castle was built in 1460 for Queen Mary of Queldres. However, as the royal family's residence was short, the castle was quickly awarded to the Sinclair family.
The Sinclairs completed the castle and built a massive 3.5 million thick wall, showing the influence of the gunpowder cannon on the castle's design.
Ravenscraig is a small castle built on a thin rocky promontory in the Firth of Forth. It is naturally defended towards the sea by cliffs on all three sides. The central part of the castle forms the northern land fortifications. It consists of two D-shaped towers with an outer wall thickness of 4.25 meters (13.9 feet) designed to withstand cannon fire. The battlements between the towers formed the fort, and the blast holes pointed to the ground. The entire area is protected by a deep rock ditch and can be accessed via a bridge.