Ključ - Credit: Wikimedia Commons
Ključ fortrass, locally known as Stari grad Ključ (), is a medieval castle complex in the village of Ključ, Gacko, Bosnia and Herzegovina. The historic area includes the Ključ fortress, the Podključ castle town (in , lit. ) as part of a wider area just beneath of the fortress, the Ključ Mosque (Ajnebeg-dede Mosque, Ključ Captains' Mosque or Starica) with a harem. The site has been declared a National monument of Bosnia and Herzegovina by the Commission to preserve national monuments of Bosnia and Herzegovina. Read more on Wikipedia
Source: en.wikipedia.org