Sanxingdui (Chinese: 三星堆; pinyin: Sānxīngduī; literally "three stars mound") is the name of an archaeological site and its deduced culture in China, now believed to be the site of an ancient Chinese city. The previously unknown Bronze Age culture was re-discovered in 1987 when archaeologists excavated remarkable artifacts, that radiocarbon dating dated as being from the 12th-11th centuries BCE. Leaving behind nothing in the historical record, not even in myth, the unknown culture that produced these artifacts is now known as the Sanxingdui Culture. A museum housing the artifacts is located near the city of Guanghan.

The Sanxingdui archaeological site is located about 4 km northeast of Nanxing Township, Guanghan County, Chengdu Prefecture, Sichuan Province. The site is a walled city belonging to the Sanxingdui Culture founded c 1600 BCE. The trapizoidal city has an east wall 2000 m, south wall 2000 m, west wall 1600 m enclosing 3.6 km². The city was built on the banks of the Yazi River (Chinese: 涧河; pinyin: Jiān Hé), and enclosed part of its tributary, Mamu River, within the city walls. The city is equal to the Shang capital Ao (Chinese: 隞; pinyin: Aó) in scale and development. The city wall were 40 m at the base and 20 m at the top and varied in height from 8–10 m. There was a smaller set of inner walls. The walls were surrounded by canals 25–20 m wide and 2–3 m deep. These canals were used for irrigation, inland navigation, defense, and flood control. The city was divided into residential, industrial and religious districts organized around a dominant central axis. It is along this axis that most of the pit burial have been found on four terraces. The structures were timber framed adobe rectangular halls. The largest was a meeting hall about 200 m².