As a result of surveys carried out by the Bulgarian-Soviet archaeological expedition, Eneolithic copper mines were discovered in southern Bulgaria in October 1971. The most interesting of these mines, Aibunar, constitutes, without doubt, one of the rarest discoveries in the history of mining not only of Europe, but also of other parts of the Old World. In the same year, Jovanović published news of finds, unique for the Balkan peninsula, of characteristic Vinač pottery found together with a zoomorphic figurine at the Rudna Glava mine in north-eastern Serbia. On the basis of these finds, he suggested an Eneolithic date for the mine. However, the remains of ancient shafts at Rudna Glava were very small, and extensive and historically well-documented mining activities of the Classical Antiquity and the Medieval period made the dating of the extant areas of ancient mining very problematic.
In contrast to this, from the moment of its discovery, the large amounts of Eneolithic pottery of Karanovo VI—Gumelnitsa type and antler tools, which were found in the mine at Aibunar, and in particular the well-dated shafts were startling. Interest in Aibunar was further increased by the discovery of seven settlement sites in an area of 15 km around the mine, with Eneolithic layers containing more than 100 pieces of oxidic copper ore. Spectral analysis showed that these pieces of ore came from Aibunar.