Mostar is a city and the administrative center of Herzegovina-Neretva Canton of the Federation of Bosnia and Herzegovina, an entity of Bosnia and Herzegovina.
Wikipedia

Bosnia and Herzegovina is a country on the Balkan Peninsula in southeastern Europe. Its countryside is home to medieval villages, rivers and lakes, plus the craggy Dinaric Alps. National capital Sarajevo has a well preserved old quarter, Ba??ar?ija, with landmarks like 16th-century Gazi Husrev-bey Mosque. Ottoman-era Latin Bridge is the site of the assassination of Archduke Franz Ferdinand, which ignited World War I.
Wikipedia