Located 7km outside of Trebinje is the old Strač Fortress, an Austro-Hungarian construction that helped to keep the strategically important town under control, for a while at least. Built between 1910 and 1916, the fortress has since fallen prey to the ravages of time but remains a fascinating visit, a blurry window into a time of empirical power and international paranoia. The future is unclear for the fortress so be sure to explore it while you can.