Fort du Salbert

Fort du Salbert is a military fortress located northwest of Belfort at an elevation of around 650 meters (2,130 feet), with interconnected underground passages running through its structure. The complex features fortified gun positions, barracks, and defensive walls built into the hillside to create a unified defense system.

The fortress was built between 1874 and 1877 as part of a wider French defense network designed to block invasion routes from the north. It remained an active military installation through much of the 20th century before being abandoned.

The fortress demonstrates how military engineers of the late 1800s designed defensive structures to control access through mountain passes. Walking through the complex shows the practical thinking behind each fortification's position and design.

The fort can be reached via marked hiking paths starting from the base of the hill, with parking available at the trailhead. The walk up takes about 30 minutes and can be steep or slippery during wet weather.

The fort used an optical semaphore system to send messages rapidly between fortifications across the region, allowing military commanders to coordinate defenses in real time. This visual communication network was far faster than written dispatches sent by horse.