Solnitsata (Bulgarian: Солницата, "The Saltworks") was a prehistoric town located in present-day Bulgaria, near the modern city of Provadia. It is the oldest salt production center in continental Europe (5500‑4200 BC). It was the first prehistoric urban center in Europe. Solnitsata was a fortified stone settlement - citadelle, inner and outer city with pottery production site and the site of a salt production facility; it flourished c. 4700–4200 BC. The settlement was walled to protect the salt, a crucial commodity in antiquity. Although its population has been estimated at only 350, Vassil Nikolov argues that it meets established criteria as a prehistoric proto-city.
Salt production drove Solnitsata's economy, and the town is believed to have supplied salt throughout the Balkans. A large collection of gold objects nearby has led archaeologists to consider that this trade resulted in great wealth for the town's residents — Varna Necropolis. Researchers suggest that some of the residential buildings in the settlement were two-story, a fact that indicates relatively advanced architectural planning in a prehistoric context. Nearby is the ancient Anhialos, whose livelihood was the extraction of sea salt. The extraction technology can be seen in the Salt Museum, Pomorie.
