Law Castle was built in 1468, on the slopes of Law Hill at West Kilbride. It was constructed as a wedding gift for Princess Mary (sister of James III) upon her marriage to Thomas Boyd, Earl of Arran.
Due to the nature of the building (being a gift to a princess) it was constructed less for fortification and more for comfort. As a result it is quite an elegant building, with more windows (and of a larger size) than was typical in similar sized castles. There were seats in the window alcoves, the interior walls were coated with mortar to ensure smooth surfaces, and all rooms had a fireplace.
The castle was last occupied in the 17th century, after which the roof blew off in a storm and it became a ruin. In the 1980’s restoration work was done to preserve the building and now the building is under new ownership and has been completely restored.