No one knows for certain how long people have lived in what is now Cambodia, where they came from, or what languages they spoke before writing was introduced, using an Indian-style alphabet, around the third century CE. Carbon 14 dates from a cave at Laang Spean in northwestern Cambodia, however, suggest that people who knew how to make pots lived in the cave as early as 4200 BCE. Another cave, near the ocean, was inhabited about a thousand years later. Presumably the first Cambodians arrived long before either of these dates; evidence of a more primitive, pebble-working culture has been found in the eastern parts of the country. Skulls and human bones found at Samrong Sen, inhabited since around 1500 BCE suggest that these prehistoric Cambodians physically resembled Cambodians today. 1