Introduction to Tongtai Bridge: Tongtai Bridge is located in the northwest of Yangyuan Mountain. It is the largest of the seven natural bridges in Danxia Mountain. The bridge is 50 meters long, has an inner arch span of 38 meters, an arch height of 15 meters, and a bridge deck width of 6-8 meters. The thinnest part of the bridge is 3 meters thick, with a smooth deck and beautiful shape. It is very similar to the Zhaozhou Bridge, the king of ancient Chinese bridges, and is known as the "No. 1 Bridge in Lingnan".