Lochnaw Castle is a 16th-century tower house five miles from the town of Stranraer, in the historical county of Wigtownshire, Scotland. The central square tower, five storeys high, formed part of the new castle.

Lochnaw Castle
Near Stranraer, Dumfries and Galloway, Scotland UK grid reference NW991628
The tower in 2007
Lochnaw Castle
Coordinates	54°55′11″N 5°08′04″W / 54.919786°N 5.134404°W / 54.919786; -5.134404
Type	Tower house
Site information
Owner	Private
Open to the public	No
Condition	Preserved
Site history
Built	16th century; extended in 17th and 18th centuries
Materials	Stone

Lochnaw Castle shows four periods of construction – a simple 16th-century keep, 17th- and 18th-century domestic dwellings, and a mansion-house, which was later demolished. There is a plaque bearing the date 1486, on the SE wall of the keep. A chapel, built in 1704, was demolished c. 1953.^[1]

An earlier, ruined castle stands on an island in the nearby Lochnaw Loch. A royal castle, this was given to the Agnews in 1363, but was sacked by Archibald The Grim, 3rd Earl of Douglas in 1390, and subsequently dismantled.^[2]

The Agnews remained in the new castle until 1948.^[3] The castle, located by the loch, is occupied as a private residence.