Strač Fortress, located 7 kilometers from Trebinje, is a massive Austro-Hungarian military stronghold constructed between 1910 and 1916 as the second-largest fortress in the Austro-Hungarian Monarchy. Built to protect the southeastern border of Bosnia and Herzegovina, the construction cost approximately 60 million euros and housed advanced military equipment including 100mm howitzers, smaller cannons, 24 machine guns, and 12 searchlights, all protected by four steel domes. Set at an elevation of 750 meters, the fortress offers panoramic views of surrounding regions and is accessible via a scenic 1.5-hour hiking trail from Trebinje's center. Though weathered by time, Strač remains a fascinating testament to early 20th-century engineering and imperial military strategy in the Balkans.