Óc Eo is an archaeological site in modern-day Óc Eo commune of Thoại Sơn District in An Giang Province of southern Vietnam. Located in the Mekong Delta, Óc Eo was a busy port of the kingdom of Funan between the 2nd century BC and 12th century AD and it may have been the port known to the Greeks and Romans as Cattigara.