On the Lijiang River, a tributary of the Lancang River about 40 kilometers northwest of Dali City, to the south of the town of Lishang Street in Dali Prefecture, there is an ancient and unique iron chain bridge, Yunlong Bridge, the only surviving ancient bridge on the "Bonan Ancient Road" on the ancient Silk Road in the southwest. Yunlong Bridge Yunlong Bridge has a long history, and has a history of more than 460 years to date.