Calvay Castle (Scottish Gaelic: Caisteal Calbhaigh) is a ruined castle on an islet close to the island of Calbhaigh, at the eastern approaches to Loch Boisdale, South Uist.
The castle is linked by a causeway from Calbhaigh, which becomes inundated at high tide.
[1] The castle may have been built by the MacRuaries of Garmoran, or by the MacNeils of Barra who were granted the lands of Boisdate in the 15th century.
[2] Bonnie Prince Charlie hid at the castle in June 1746, while fleeing from the Duke of Cumberland's troops after the Battle of Culloden.
[2] The island also has a lighthouse, built by David Alan Stevenson in 1891.