Val Camonica likely became habitable only around 15,000 years ago, at the end of last Ice Age, with the melting of the glacier that first carved out the valley. It is likely that the first humans visited the valley in epipaleolithic times, and appear to have settled by the Neolithic period. When the Ancient Romans extended their dominions north of the River Po, they encountered a people called the Camunni, of unknown origin, populating the valley. About 300,000 petroglyphs survive from this period. By the end of the first century BC, the Valle Camonica was ruled by Ancient Rome, which established the city of Cividate Camuno, with baths, an amphitheater and a large temple dedicated to Minerva.