Pre-history
There is sparse evidence for a Pleistocene human occupation of present day Cambodia, which includes quartz and quartzite pebble tools found in terraces along the Mekong River, in Stung Treng and Kratié provinces, and in Kampot Province, although their dating is unreliable.
Some slight archaeological evidence shows communities of hunter-gatherers inhabited Cambodia during Holocene: the most ancient Cambodian archeological site is considered to be the cave of L'aang Spean, in Battambang Province, which belongs to the Hoabinhian period. Excavations in its lower layers produced a series of radiocarbon dates as of 6000 BC.
Upper layers in the same site gave evidence of transition to Neolithic, containing the earliest dated earthenware ceramics in Cambodia
Archeological records for the period between Holocene and Iron Age remain equally limited. Other prehistoric sites of somewhat uncertain date are Samrong Sen (not far from the ancient capital of Udong), where the first investigations began in 1877, and Phum Snay, in the northern province of Banteay Meanchey. Prehistoric artifacts are often found during mining activities in Ratanakiri.
The most curious prehistoric evidence in Cambodia however is the various "circular earthworks", discovered in the red soils near Memot and in the adjacent region of Vietnam in the latter 1950s. Their function and age are still debated, but some of them possibly date from 2nd millennium BC at least.
A pivotal event in Cambodian prehistory was the slow penetration of the first rice farmers from the north, which began in the late 3rd millennium BC.
Iron was worked by about 500 BC, with supporting evidence coming from the Khorat Plateau, in modern day Thailand. In Cambodia, some Iron Age settlements were found beneath Baksei Chamkrong and other Angkorian temples while circular earthworks, were found beneath Lovea a few kilometers north-west of Angkor. Burials, much richer
