Ouvrage Cap Martin is a work (gros ouvrage) of the Maginot Line's Alpine extension, the Alpine Line, also called the Little Maginot Line. The ouvrage, located on high ground in Roquebrune, consists of two artillery blocks and one combination block facing Italy. The ouvrage was at the southernmost end of the Alpine Line and overlooked the Mediterranean Sea coastline at an altitude of 21 meters between Nice and Menton, facing towards Italy.