Babak Castle also known as the Immortal Castle or Republic Castle is an impressive and huge building citadel on the top of a mountain, which is located 16 km southwest of Kaleibar City in northwestern Iran. It was the stronghold of the Iranian hero, Bābak Khorramdin who fought the Arab invaders.
Every July 10th, Iranian pilgrims attend at the castle to honor and celebrate the life of their national hero, Babak and his companions, for sacrificing their lives to defending Iran and Iranian way of life.
The castle, built on 2300-2600 meter heights, surrounded by gorges as deep as 400 to 600 meters, is believed to belong to the Parthian dynasty and modified under the Sasanid dynasty. To reach the castle, one has to trek a tortuous and narrow passageway and then cross a corridor-shaped temple, 200 meters in lengths.