Zhaozhou Bridge is also called Anji Bridge. It is on the Jiaohe River to the south of Zhaoxian County town, 45 kilometers southeast of Shijiazhuang, Hebei Province. Because lhe whole bridge was made of stone materials, it was called Big Stone Bridge by the local people. It was first built between 595 ~605 and the construction was supervised by Li Chun, a famous craftsman in the Sui Dynasty. The structure of Zhaozhou Bridge is original, and the appearance is beautiful. The ancient people said that "The architecture is so novel that nobody knows how it was constructed. " The bridge is 64.4 meters long, 9.6 meters wide and the span is 37. 2 meters. It is a single-hole arc bridge made up of 28 comparatively separate arches. The greatest scientific contribution of Zhaozhou Bridge is its pioneering work of "open spandrel". At each shoulder of the main arch, there are 2 small parallel arches. This not only increases passages for the running water, decreases the weight of the bridge, and saves stone materials, but also enhances the stability of the bridge. Therefore, though l ,400 years has passed, having undergone many floods, eight earthquakes, and heavy traffic, it is still standing firm over the Jiaohe River. There are many beautiful legends about the construction of Zhaozhou Bridge. In the past, the Jiaohe River overflowed, and the local people could only ferry across by boat. Lu Ban, the carpenters' ancestor, turned the sheep into stones overnight to make the bridge. Zhang Guolao and Chai Wangye, two immortals, came to test the solidity of the bridge. Zhang Guolao rode on the don-key-back, facing backward. In the long bag on the donkey-back, there were the sun and the moon. Chai Wangye pushed a one-wheeled cart, on which there were the five famous mountains in China. When they came to the middle of the bridge, it began to shake and was likely to fall down. Seeing the situation was unfavorable, Lu Ban jumped into the water, and held up the bridge with his hands. Luckily, the bridge was safe and sound. So there left on the surface of the bridge clear hoof prints of the donkey and a rut. Lu Ban's fingerprints were also left on the arch of the bridge. Just like what was sung in the folk song "Child Cowherd", "Zhaozhou Bridge was built by Lu Ban, and the boulder railings were left by sages. Zhang Guolao passed the bridge on the donkey-back, and Chai Wangye made a rut by pushing the cart on the bridge. "