The legendary Iron Gates were located in Boysun. They consisted of an artificial barrier in the mountain canyon, built to regulate the caravan trade and customs. They were well-known at the Great Silk Road. According to Chinese traveller Xuan Tzang, in the 7th century there were wooden gates coated with iron, with numerous bells. The customs station operated for many centuries, and the beginning of the 15th century still brought, good income to Amir Temur. The Iron Gates were located on the old road in the canyon of Dara-i Buzgala-khana 3 km to northwest from Shurob kishlak. The canyon is 2 km in length and from 10 to 50 m in width. «Dara-i Buzgala-khana» means «Canyon of the Fallow-Deer’s House», that could be connected with a legend about Chinggis-khan who met a talking-fallow-deer at the Iron Gate and followed its advice to stop his conquest. The «Cave» sura from the Koran also mentions the construction of a metal barrier against wild tribes of Goghs and Magoghs initiated by Iskander Zul-i-Karnain (Alexander the Great). The oriental tales about Alexander refer to it as the Iron Gate, and Alisher Navoi called it the «Bank of Iskander». Such a legend could have arisen from the fact that during two millennia at the strategic mountain pass of Boysun there were first the defensive structures of the Greco-Macedonians, which then became a part of Kushan defensive complex and later, the customs station with the Iron Gates.