[Tunxi Old Bridge], famous Zhenhai Bridge. Located in Tunxi, the seat of Huangshan City, Anhui Province. It was built in 15 years (1536) in Mingjiajing, and has a history of more than 480 years. It is one of the rare large ancient stone arch bridges in Anhui Province. The old bridge is located at the intersection of Tunxi Sanjiangkou, Xin'an River, Rate Water and Hengjiang River. It stands on the Hengjiangkou. It runs through Tunxi Old Street and Liyang. It was a gateway to and from Tunxi in the old days. It is now an important passage to Huangshan Airport, the western suburbs and Jiangxi Wuyuan. It is a key cultural relics protection unit in Huangshan City. And it is still in use. This bridge is a six pier seven-hole stone arch bridge, 133 meters long, 15 meters wide at both ends, 10 meters high, and 13 meters long. The upper part is an equal section of solid belly stone arch, and the lower part is a grouted stone gravity pier. The pier is an isoscele triangle, the water head of the water head stone tip up, resulting in the bow shape, the back of the stone pier is the back of the turtle, as if six stone turtles are carrying the bridge.