Claim: Chushul Chakzam, a suspension bridge which literally means “iron bridge”, was built in 1430 by Thang Tong Gyalpo.
Evidence: The Chushul Chakzam (Tibetan: ཆུ་ཤུལ་ལྕགས་ཟམ), or simply Chakzam which literally means "iron bridge" in Standard Tibetan, was a suspension bridge that spanned the Yarlung Tsangpo river in modern-day Qüxü County near Lhasa, Tibet. 1430 (1430) It was built in 1430 by Thang Tong Gyalpo.