Strač Fortress

Strač Fortress is an Austro-Hungarian fortification southeast of Trebinje, located at 750 meters above sea level with panoramic views of Zupci, Petrovo Polje, the Trebinje Forest and the city. It was built from 1910 to 1916 as part of a system of ten fortifications with which Austria-Hungary defended Trebinje and the Bay of Kotor. It was the second-largest Austro-Hungarian fortress in the monarchy, and construction cost the equivalent of 60 million euros.

Unlike other fortifications from that period, Strač is built into the ground, which earned it the reputation of being the most mysterious structure. It had 60–65 rooms, its own diesel generator, water tanks, and a cableway for delivering materials. The ~55-ton domes were transported by a tractor designed by Ferdinand Porsche. Two steel domes have survived to this day and are the only ones of their kind in Europe. Ownership of the fortress has not been resolved, and it is not officially a protected cultural monument.