Ouvrage Boussois, Military fortification in Boussois, France.

Ouvrage Boussois is a military fortification in Boussois, northern France, with three infantry blocks connected by underground galleries. Inside are spaces for barracks, ammunition storage, and operational facilities needed to run the installation.

The fortification was built in the 1930s as part of modern French defensive planning. German forces captured it during both World Wars, first in 1914 and again in 1940.

The structure shows French military engineering from the 1930s and connects elements from the earlier Séré de Rivières fortification system. This link reveals how French defensive building traditions developed over several decades.

The Maginot ouvrage is closed to access, and its surface lies overgrown with weeds and thorns. The site sits on hill 166 north of the D 959 between Boussois and Marpent, with no visitor facilities. The old fort and the ouvrage share the same ground, so the remains are seen from outside only.

The Maginot ouvrage was built inside the walls of the old Fort de Boussois, and construction was complicated by old mines beneath the site. During four days of fighting in May 1940 it fired 500,000 machine-gun cartridges, 1,400 mortar shells, 500 25 mm shells and 160 47 mm shells.