About an hour southwest of Hoi An, is the archaeological site of Mỹ Sơn: the religious and ceremonial center of the Champa people, who once ruled central and southern Vietnam. With ruins dating between the 4th and 13th century AD, no less an authority than UNESCO describes the monuments of Mỹ Sơn as "unique and without equal in Southeast Asia".
Until the end of the 18th century, Hoi An was Vietnam's main port-of-call, and home to a large number of foreign traders. Above all, the city was popular with the Chinese, many of whom established a permanent presence among the Vietnamese. Communities from the various regions of China built Assembly Halls: social and religious buildings in which they could congregate and worship their ancestral gods.