There are several castles with the name Knock. This one is also known by an older name Caisteal Camus and sometimes Caisteal Chamius. There was originally a dun (or fort) on this promontory and the castle was built on the remains. Knock is a 15th century keep constructed by the MacLeods and later captured by the MacDonalds.
It was remodeled in 1596 by the MacDonalds but was abandoned by 1689. Most of the stone was used for nearby buildings. This castle is said to be haunted by a Green Lady. She doesn't have much left to haunt!
Additional photos by Contributors