site.btaArchaeologists Uncover Mysterious Construction Rituals and Strange Offerings to Household Spirits at Provadia–Solnitsata

During excavation work at the prehistoric Solnitsata Complex near the town of Provadia, Northeastern Bulgaria, archaeologists stumbled upon intriguing construction mysteries and unusual ritual offerings made to household spirits, Academician Vasil Nikolov, head of the excavations, told BTA, speaking about this summer’s archaeological discoveries.

This season, the archaeological team focused more intensively on the burial mound built on top of the prehistoric settlement. The mound dates back to the early Roman period and is enormous, rising 13 meters high with a base of about 80 meters, Nikolov said. He explained that it likely consists of several separate mounds that eventually merged into one. “We haven’t yet reached any burial complexes,” he added.

This year’s work mainly prepared the site for next year’s excavations, when the team plans to explore two buildings belonging to a Thracian aristocrat discovered in the northwestern part of the mound. The structures were partially destroyed in Late antiquity, and Nikolov said that they should not only be studied but also conserved and, if possible, partially restored. The Thracian nobleman seems to have settled on top of the prehistoric site, in its southern part, archaeologists uncovered a sanctuary with ritual pits. After his death, or perhaps after the death of his descendants, the massive mound was formed, Nikolov said.

The solid buildings, uncovered during the excavations, had stone foundations and sundried brick walls. “Based on the evidence, they date to the late 1st century BC or early 1st century AD, more likely before the birth of Christ. They were luxurious, solid constructions, with light-coloured plastered interiors,” Nikolov said. Next year, the team plans to excavate deeper into the mound and study the remains of both houses in detail. The archaeologist believes their owner was connected to salt production, “a very wealthy man, as evidenced by fragments of fine Hellenic pottery, which was extremely expensive for the time, and the rich offerings found in the ritual pits.”

The main focus of Nikolov’s team remains the prehistoric layers. This summer, they worked on the southern part of the ancient settlement mound, where they found the remains of houses, mostly two-storey ones. One of the excavated buildings, a square structure with unusually deep trenches, likely dates to the very end of the Chalcolithic period, when climate change forced the settlement’s abandonment. “What’s strange,” Nikolov said, “is how deep the foundations are. You can see the postholes of the wooden pillars that supported the structure. It was probably a two-storey building, like the others, but we’ve never seen trenches like this before.”

Numerous artifacts were discovered during the season’s work, including beautifully crafted pottery, some of which has already been restored. Because salt production was the settlement’s main occupation, its people were wealthy and cultivated, with advanced material culture. Some of the ceramics were locally made, but Nikolov believes most were commissioned from craftsmen in nearby villages, since the salt producers likely had little time for pottery-making themselves. The settlement’s population is estimated at around 400 people, including children. They were busy with the salt production, defending the settlement, and upkeeping the fortifications. “This prehistoric community disproves the idea that hired labour appeared only with capitalism,” Nikolov said. He believes the salt producers hired workers from neighbouring communities, paying them in salt.

The excavations confirmed that the fortified settlement was periodically attacked. Many arrowheads were found, suggesting others wanted its profitable trade. There’s no evidence it was ever captured, though. The finds also show there were at least two distinct clans, evident of the salt-production facilities. Each clan had its own and likely sold its own production. These findings, Nikolov said, challenge the conventional theory of when humans first developed a sense of ownership. “Personal ownership, not private property, emerged at this time,” he added.

Among the most fascinating discoveries this year were unique construction sacrifices dating to the middle of the 5th millennium BC, Nikolov said. People felt deeply connected to nature and would ritually enclose the space, before building a home, by ploughing a magical circle around it. Future residents sought harmony with the household spirit guarding the site, offering sacrifices to secure its protection. These were not human sacrifices, but objects, food, or animal remains.

For the first time, archaeologists found a house containing several such construction sacrifices. “We don’t know why so many were needed,” Nikolov added. One offering included a skull, possibly belonging to a deer and a horn, ceramic vessels, and a flint axe. Beautiful pottery was found at another location. A third contained the bones of a dog, over 20 flint tools, and three small stone chisels and axes. The house belonged to one family, but why it required so many offerings remains a mystery, Nikolov said, adding he had never seen anything like it.

Traditionally, offerings were placed under the floor before the house was built. In this case, however, the area had been ritually cleansed with fire, which is rare. Another puzzling find was a clay figure placed in the floor of a different house, a head with ears and two holes, almost like an angry little face, resembling present day emoji, Nikolov said.

Archaeologists uncovered evidence of how ancient people used red ochre to decorate pottery and paint on walls. They first ground it, mixed it, possibly with water, poured it into moulds, and let it dry. Thus, producing something like chalk for drawing and decorating. Fragments of something that could be called wall paintings were found, but they are too fragmented and unclear.

One of the remaining puzzles for the head of the excavation team is how these people built such tall houses, two and even three storeys high, what were the support beams they used. This year, the archaeologists continued studying an oven, weighing over a ton, found on the second floor of a building. Even without it, it’s unclear how the structure bore the load, since the floors were plastered annually with layers of clay, sometimes more than 50. Nikolov said he had asked modern engineers how they think their colleagues from 7,000 years ago managed this but still hasn’t received an answer. 

One mystery has been solved, the purpose of strange round bird-shaped vessels with spouts that had puzzled archaeologists. Nikolov found the answer in century-old publications about the construction of the modern saltworks near Provadia. Ancient installations were massive, producing up to five tons of salt. The mysterious vessels, fitted with wooden handles, were used to pour brine during production to obtain high-quality salt.

“Provadia–Solnitsata is a unique monument of European prehistory,” Nikolov said. Archaeologists focus not only on excavations but also on the conservation and public presentation of the site. “It’s an active archaeological site, but we welcome visitors, guide them, and tell them the story,” he said. There’s still much work to be done, and the site holds invaluable information that must be shared.

The Provadia–Solnitsata prehistoric site is the oldest salt-production centre in Europe (5600–4350 BCE) that turned into the first known prehistoric urban centre on the continent. Solnitsata will be part of the future European Salt Heritage Route, a cultural corridor highlighting ancient salt-production centres, Nikolov added. The network, linking sites in Poland, Romania, Serbia, Hungary, Germany, France, and Italy, is being developed in partnership with the European Institute of Cultural Routes (Luxembourg) of the Council of Europe. The project could become reality within two years, Nikolov believes.