History: Details on the Construction and Purpose of the Bunker

The most closely guarded secret of Socialist Federal Republic of Yugoslavia (SFRY), D-0—originally codenamed “Istanbul” and later known as the “Atomic War Command” and “Army Reserve Command,” but most famously called Tito’s Bunker—continues to attract and intrigue countless visitors from around the world every year. Seemingly just an ordinary little house, for many years it concealed the most tightly guarded secret of the former SFRY. Hidden deep within Mount Zlatar, built in absolute secrecy over 26 years from 1953 to 1979, the complex stands as a testament to the remarkable skill of its builders. Its perfectly preserved infrastructure systems showcase the high quality of the installed equipment, machinery, and devices, most of which were products of domestic Yugoslav industry. All workers involved in its construction were carefully selected, signed strict confidentiality agreements, and underwent extensive security screening. Its construction cost the equivalent of 4.6 billion US dollars at the time, which today would amount to over 10 billion US dollars. This facility was the third-largest investment of the former SFRY, alongside the Željava military airbase near Bihać and the Lora naval port in Split. Information about the bunker was known only to Tito, the Chief of the Federal Secretariat for National Defense (SSNO), the Chief of the General Staff of the Yugoslav People’s Army (JNA), the Head of the First Directorate of Security, and the Chief of Communications of the SSNO. The primary purpose of the D-0 ARK facility was to accommodate, shelter, and protect the Supreme Command Headquarters, key members of the Presidency, and the Yugoslav Government, ensuring optimal conditions for work, leadership, and command of the country during crises or in the event of a nuclear attack. After the breakup of Yugoslavia, the facility remained under the protection of the Army of the Federation of Bosnia and Herzegovina for many years. In 2003, the bunker’s existence was officially confirmed to the public for the first time. Today, it no longer serves a military purpose but has been transformed into a museum and gallery space.