Ouvrage "G" de la D.A.T.

Ouvrage G is a military fortification on Salbert Hill near Belfort built with extensive underground chambers and radar systems spread across multiple levels. The complex integrates the Fort du Salbert with a network of tunnels and shelters carved deep into the rock.

This air defense installation was built between 1953 and 1958 during France's NATO period as a response to Cold War security concerns. Within a year of completion, rapid advances in radar technology rendered it obsolete for active military use.

The facility maintained different security clearance levels for military personnel, marked by color-coded room access throughout the underground structure.

The site is maintained by the ATOMES association and is undergoing restoration work to gradually open more areas to visitors. It is helpful to check ahead about which sections are accessible during your visit, since not all parts are continuously open.

The bedrock still shows visible marks from the excavation techniques used during construction in the 1950s. These traces reveal how workers shaped this underground complex using the tools and methods available at that time.