In 1999, the Tang Luoyang City Archaeological Team, IA, CASS, discovered and excavated vestiges of a defensive ditch of the Northern Song period and the remaining city-wall and protecting slope related to them in the old-city area of Luoyang. The excavation covered an area of about 935 sq m. The ditch runs in the north-south direction, has an inverted trapezoidal section and contains mainly alluvial deposits. The protecting slope lies on the western side of the ditch and is built of rammed earth.The city-wall is constructed from the foundation trench surviving from the eastern wall of the East City of Luoyang. The unearthed objects include pottery, porcelain, coppers and bronzes and iron artifacts, with copper coins, bronze mirrors and porcelain articles of the Northern Song period as the main part. The excavation provided material data for understanding the location of and spatial distance between the city-wall and the moat in ancient China, as well as the building method and characteristic features of the moat.
