39°37′01″N116°03′22″E / 39.616908°N 116.056000°E /39.616908; 116.056000
TheXiadu orLower Capital of Yan (Chinese:下都;pinyin:Xiàdū) was one of the capitals ofYan during theWarring States period of ancient China. Xiadu may have beenthe largest city in the world from 400 to 300 BC, with an estimated peak population over 300,000.[1]
The remains of the city are located inYi County,Baoding,Hebei Province. At 30 km2, Xiadu is the largest excavated city from the Warring States period. Xiadu was surrounded by amoat andrammed earth wall; the base of the city walls measured 40 m at its widest. A portion of the old city wall, measuring up to 6.8 m high, still remains today. The ruins were first excavated in 1929 by an archaeological expedition fromPeking University.
The city was built in theTaihang Mountains, flanked by theBeiyi River to its north and by theZhongyi River to its south. The difficult topography made it easy to defend from attack. The city was square, with a wall andcanal running north–south through its center, dividing the city into eastern and western halves. Large workshops for casting iron, casting bronze, minting coins, making weapons, making pottery and making bone objects were all found in the eastern city. The palace and royal cemeteries were also located in the eastern city. Two cemeteries were discovered; 13 and 10 tombs were found in each. All the tombs were covered by a pyramidaltumulus. A museum about the discovered objects was built in Beijing.[2]