Zhaozhou Bridge: the world's oldest single-arch bridge -
Zhaozhou Bridge is in Zhaoxian County, North China's Hebei province, around 300km south of Beijing. Built in Sui Dynasty (581-618 AD), it is the world's oldest single-arch bridge, with a span of 37 meters.
Along with such world famous landmarks as the Forbidden City and the Great Wall, the bridge was listed into China's first group of national cultural heritage protection sites in 1961.