Registered as a UNESCO World Heritage Site, the 6th-century Derbent (Darband) fortification complex is considered the largest defensive structure of Sasanian Persia (Iran) in the Caucasus. “Derbent: What Persia Left Behind”, also explores the unique architecture of the massive fortress, and how it has been preserved for some fifteen centuries by Persian, Arab, Turkish and Russian rulers. Built strategically in the narrowest area between the Caucasus Mountains and the Caspian Sea, the fortification includes the northernmost Middle Persian (Pahlavi) inscriptions in the world, which are in danger of destruction. The 42-km defence wall of the complex that extended toward the Black Sea had already been destroyed in the Soviet era.