This photo series by CGTN photographers reveals the secrets of the Citadel of Herat, locally known as Qala Iktyaruddin. 

One of the oldest structures in the historic core of Herat, the citadel was reputedly established by Alexander the Great in around 330 BC, while its extant battlements and towers are thought to date from the early 14th century AD. 

During the Timurid rule, Timur's son Shah Rukh made Herat the Timurid capital, where he rebuilt the citadel, including commissioning the tilework that is still visible on several towers. The citadel underwent restorations both in the 1970s and in the 2000s.