One of the earliest Neolithic sites in the Indian subcontinent is Bhirrana along the ancient Ghaggar-Hakra (Saraswati) riverine system in the present day state of Haryana in India, dating to around 7600 BC. Other early sites include Lahuradewa in the Middle Ganges region and Jhusi near the confluence of Ganges and Yamuna rivers, both dating to around 7000 BC. The aceramic Neolithic at Mehrgarh lasts from 7000 to 5500 BC, with the ceramic Neolithic at Mehrgarh lasting up to 3300 BC; blending into the Early Bronze Age. Mehrgarh is one of the earliest sites with evidence of farming and herding in the Indian subcontinent. It is likely that the culture centered around Mehrgarh migrated into the Indus Valley and became the Indus Valley Civilisation. The earliest fortified town in the region is found at Rehman Dheri, dated 4000 BC in Khyber Pakhtunkhwa close to River Zhob Valley. Other fortified towns found to date are at Amri (3600–3300 BC), Kot Diji in Sindh, and at Kalibangan (3000 BC) at the Hakra River.