Kaleybar  is a city in and the capital of Kaleybar County, East Azerbaijan Province, Iran. In recent year the city has become a tourist destination thanks to its proximity to Babak Castle. In addition, as a result of geopolitical developments Kaleybar is gradually replacing Ahar as the capital city of Qareh Dagh region. Pāpak Fort or Babak Castle, also known as the Immortal Castle or Republic Castle, is a large citadel and National Symbol of Iranians on the top of a mountain in the Arasbaran forests, which is located 6 km southwest of Kalibar City in northwestern Iran.