Lamonzie-Montastruc (French pronunciation: [lamɔ̃zi mɔ̃tastʁyk]; Occitan: La Móngia de Montastruc) is a commune in the Dordogne department in Nouvelle-Aquitaine in southwestern France.

One is Le Château de Montastruc, an antique troglodytic site, then a fortress, arranged progressively through its 1500 years of history.

Le Château de Montastruc is listed as a French Historical Monument.

The other is Le Château de Bellegarde, originating from the 14th Century, although the interiors are of the 20th century.

This Dordogne geographical article is a stub.