Archaeologists have discovered remnants of a 4,000-year-old Chalcolithic civilisation in the greater Bengal region, and believe the finds are one of the earliest signs of settlement in the region. However, evidence of much older Palaeolithic human habitations were found in the form of a stone implement and a hand axe in Rangamati and Feni districts of Bangladesh. The origin of the word "Bangla ~ Bengal" is unknown, though it is believed to be derived from a tribe called "Bang" that settled in the area around the year 1000 BCE.