Human habitation of present-day Sweden began around 12000 BC. The earliest known people belonged to the Bromme culture of the Late Palaeolithic, spreading from the south at the close of the Last Glacial Period. Neolithic farming culture became established in the southern regions around 4000 BC, but much later further north. About 1700 BC the Nordic Bronze Age began in the southern regions, based on imported metals; this was succeeded about 500 BC by the Iron Age, for which local ore deposits were exploited. Cemeteries are known mainly from 200 BC onward.