Like so many military installations from the Yugoslav era this aircraft hangar outside of Mostar lies abandoned, but can be still be visited by anyone looking for a bit of off-the-beaten-path urban exploring. 

The abandoned aircraft hangar in the village of Gnojnice outside of Mostar is a haunting arch built right into a weedy hillside. The high, cement ceiling is molded into a smooth curve, creating a huge concrete cavern filled with nothing but debris and echoes. There are exits on either end of the tunnel and giant blast doors can still be found within. 

According to travel blogger Cheryl Howard who visited the hanger with a local guide, the abandoned airplane garage was once a top secret facility hidden next to the Mostar airport. Yugoslavian revolutionary Josip Tito had fighter jets placed deep in the mountainous bowels of the hangar, ready to deploy. The natural fortress protected the planes from attack, as well as from the prying eyes of citizens and spies.

Today the hangar lies abandoned in complete darkness with debris and broken glass everywhere. The old, abandoned cavern is not an official tourist attraction, but for the determined, this little bit of top secret history can be sought out. Just be sure to bring good shoes and a flashlight lest you become the last casualty of war.