The archaeological site of Provadia-Solnitsata is a prehistoric tell over which a big Thracian burial mound was heaped much later. It is situated in the region of Provadia, in Northeast Bulgaria.
The tell site lies over the biggest rock salt deposit in the Eastern Balkans from which salt springs issued. The production of salt started during the late Neolithic, i.e. between 5,400 and 5,200 BC. Salt was produced through boiling of brine from the springs in thin-walled ceramic pots put in solid dome ovens within the settlement. This is the earliest example in Europe of such salt production technology and Provadia-Solnitsata is the oldest salt production center in the Old World known so far. Life at the tell continued through the Middle Chalcolithic, i.e. between 4,650 and 4,500 BC and by the end of this period a big production complex developed next to the settlement which existed also in the Late Chalcolithic, i.e. between 4,500 and 4,200 BC. The ovens were replaced by open wide pits in which new type of ceramic pots were arranged one beside the other: deep thick-walled tubs with very large capacity. Brine was boiled on open fire blazed in the bottom of the pit among the vessels. The salt production and trade at that time led to the accumulation – through exchange – of exceptional ‘wealth’ of prestigious objects at the Varna Chalcolithic cemetery (4,500 – 4,200 BC) 37 kilometers east of Provadia-Solnitsata.