As the Stone Age moved into the Bronze Age, known as the Eneolithic period, in which the first metal - copper - began to be used, the Vučedol culture arose (c. 3000 BC - c. 2200 BC), named after the locality of Vučedol, on the bank of the Danube near Vukovar. Vučedol, near Vukovar, an important prehistoric site (‘The Troy of the Danube'), after which the Vučedol culture was named, and which embraced a wider cultural complex from the Carpathians to the eastern Alps and the Dinaric Alps. It is presumed to have emerged after the arrival of Indo-European settlers around 3,000 BC and lasted until about 2,000 BC. Its characteristics include new metalwork procedures, extremely skilled ceramics, and, according to some researchers, the people used a calendar marked on ceramic vessels.