The Sudel Observatory

After the Franco-Prussian War of 1871, the Treaty of Frankfurt assigned Alsace to Germany. The canton of Masevaux, previously attached to the Belfort district, was then cut off from its French-speaking part and became German. The new border followed the Vosges ridge, and the summit of Sudel, reaching 920 meters, offered a strategic view of the fortified city of Belfort. In 1911, German authorities installed a 40-meter-high observatory there, raising concerns among the French general staff who saw it as a threat to the security of their troops stationed in the region.

In October 1913, the watchtower collapsed after its six wooden pillars were sawed through. The sabotage was attributed to a group of loggers from Rougemont-le-Château. The French authorities, fearing reprisals from Germany, officially attributed the act to vandalism. Despite this incident, German army engineers rebuilt a new observatory in December 1913, this time 30 meters high, made from fir trees 30 to 40 centimeters in diameter.

This structure stood only briefly: at the start of World War I, on August 6, 1914, it was destroyed by soldiers of the 171st Infantry Regiment of Belfort.