The earliest "Homo sapiens" presence in Mainland Southeast Asia can be traced back to 50,000 years ago and to at least 40,000 years ago in Maritime Southeast Asia. As early as 10,000 years ago, Hoabinhian settlers had developed a tradition and culture of distinct artefact and tool production. During the Neolithic, Austroasiatic peoples populated Indochina via land routes and sea-borne Austronesian immigrants preferably settled in Maritime Southeast Asia. The earliest agricultural societies that cultivated millet and wet-rice emerged around 1700 BCE in the lowlands and river floodplains of Indochina.