Fortress of Ključ
Ključ, Bosnia and Herzegovina
Ključ Fortress is a medieval fortress in Bosnia and Herzegovina, above the modern-day town of Ključ. It is located on an elongated slope on high rocks that dominate the valley of the river Sana. Before it was redeveloped, there was a small ancient fortress from Roman times.
Fort data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).