Here’s what you’ll learn when you read this story:

• Archaeologists in Romania have uncovered portions of an ancient megastructure from around 6,200 years ago.
• The oak-floor building was located at the entrance to a settlement that included roughly 45 houses.
• The megastructure is only the sixth of its kind ever found, and experts are planning further research and excavation at the site.

Excavations in the hills of northeastern Romania have unearthed one of the world’s oldest known megastructures, a massive communal building dating to around 4000 B.C.E. that still holds plenty of secrets after only a quarter of the site has been excavated.

The building sits at the center of a settlement called Stăuceni-Holm in Romania’s Botoșani County, a site first identified in the 1960s but not excavated until 2023. It belongs to the Cucuteni-Trypillia culture, a network of farming communities that spread across modern-day Romania, Moldova, and Ukraine from roughly 4800 to 3000 B.C.E. According to a study published in PLOS ONE, the structure is only the sixth megastructure from this culture ever to be excavated, and radiocarbon dating makes it one of the earliest examples on record.

At roughly 350 square meters, the building dwarfs the ordinary houses around it, and its prominent position near the settlement's entrance suggests that it played a special communal role. The Stăuceni-Holm settlement itself is relatively modest, home to an estimated 320 to 350 people, far smaller than some Cucuteni-Trypillia mega-sites in Ukraine that likely housed thousands. Yet even this smaller community built the same kind of oversized gathering place, a pattern that suggests megastructures were a standard organizational feature of the culture rather than a phenomenon limited to its largest towns. With three-quarters of the site still unexcavated, researchers expect the building has much more to reveal about how these early European communities lived and governed themselves.

The megastructure’s scale suggests that it held great significance for the people who built it. The rectangular building of over 3,700 square feet sat between defensive ditches and a palisade system at the entrance to the settlement. At three to five times larger than any of the homes, the structure offers a stark contrast to the rest of the settlement.

Inside, the oak wood floor covered in burnt clay contained a dense concentration of pottery pieces, including a “remarkable” example of a carved bull’s head attached to a bowl. Excavations also revealed a conical idol with an unknown purpose, although it’s a common find among Cucuteni sites. Three ladles were found, including one with painted patterns, along with a grooved pottery vessel painted in red ochre. Flint tools were found throughout the building.

Originally, the megastructure may have had an upper floor built like an open-air terrace. The inner portion had several rooms, likely for living, cooking, storage, and maybe even ritual purposes. Amid the remains of cereals and fruits, the team found henbane seeds, a psychotropic plant common in both medicinal and ritual use over 6,000 years ago.

While early geomagnetic surveys indicated the building featured hearths and storage pits, actual excavation proved that wrong. The authors wrote that at this stage of the research it’s “unrealistic to consider the function of the building as storage building or a communal place for consumption of food.” And there’s no real indication it was strictly a cult building. “Perhaps the megastructure was just a bigger house for a bigger family, a communal building for decision making, or a meeting place for special high-ranking inhabitants reflecting the change toward a more hierarchized organization of the community,” they wrote.