Castle Sinclair Girnigoe is the only castle in Scotland to be listed by the World Monuments Fund. This once impregnable medieval / renaissance stronghold is now the most spectacular ruin in the North of Scotland and is the subject of a preservation programme by its owner, The Clan Sinclair Trust, which is a limited company (Number SC 194021) with charitable status (Number: SC 028778).
More information can be found on http://www.castlesinclairgirnigoe.org