Archaeologists in northwest China's Shaanxi Province have discovered a large-scale relic site estimated to be 2,200 years old on the outskirts of the provincial capital Xi'an.

    The site is the biggest of its kind that has been excavated in the past three decades within the palace group of Changle Palace, the imperial residence palace of the imperial Western Han Dynasty (206 B.C.-24), archaeologists said.

    The unearthed ruins, which lies in the northwest part of the palace group, is 160 meters long east-to-west and 50 meters wide north-to-south, with a rammed earth structure at its center, according to initial excavation.

    Archaeologists have also spotted two courts in the northeast part of the structure, each installed with a sedimentation tank. They are separated by a adobe wall but linked underground by a ceramic pipe. And two other pipes, each over 30 meters long, are used to drain the water stored in the tanks.

    According to Liu Zhendong, an archaeologist with the Institute of Archaeology of the Chinese Academy of Social Sciences, who leads the archaeological team, the newly discovered ruins is probably the main structure, namely the front hall of the Changle Palace, where the imperial court affairs are mulled and handled.

    Liu also implied that there could be a passageway to link the site with the site unearthed earlier, which is only 30 meters apart and believed to be the imperial residence of Western Han Dynasty.

    The discovery will offer a new clue to the studies of the layout and the history of ancient Chinese palaces, Liu said.