La Batterie du Glacis
La Batterie du Glacis (Glacis Battery) was built in 1898 to mount four 270 mm (10.5-inch) High Angle Fire guns. The guns were in barbette emplacements with underground magazines and shelters. The original underground works remain largely intact.
The original emplacements have largely disappeared with the building of a British 6-inch battery and Defence Electric Light (DEL du Gros Rocher) in 1942. Some observations positions also appear to have been build over the old battery.