A Mediterranean blueprint in Celtic Europe
Overlooking the Danube River, the Heuneburg hillfort is different from typical Iron Age Celtic construction. Around 600 BCE, its inhabitants erected a fortification using a technology completely foreign to the region: a mud-brick wall on a stone foundation. This building method was common in the Greek and Etruscan cities of the Mediterranean but was otherwise unknown north of the Alps at that time. The wall, likely coated in white plaster, stood up to four meters high and was punctuated by projecting towers. This structure enclosed a 3.3-hectare citadel, or acropolis, forming the core of a much larger settlement.
Archaeological investigations have revealed a densely populated urban center. The complete settlement covered about 100 hectares, including the fortified acropolis, a lower town, and an extensive outer settlement of farmsteads. This proto-urban center housed an estimated 2,000 to 5,000 people. Some scholars suggest this might be the lost Celtic "Polis of Pyrene" mentioned by the Greek historian Herodotus in the 5th century BCE, although this connection remains speculative. The mud-brick phase of the settlement ended with a fire around 530 BCE, after which the inhabitants rebuilt the fortifications using traditional local techniques with wood, stones, and earth.
An Iron Age trade hub
The Heuneburg's unique architecture was a product of its deep connections to the south. Positioned on the upper Danube, it controlled a major trade corridor connecting northern Europe with the Mediterranean. Excavations have unearthed a amount of imported luxury goods that show it was a commercial powerhouse. Artifacts include black-figure pottery from Athens, wine amphorae from Etruria and the Greek colony of Massalia (modern-day Marseille), and jewelry made of coral from the Mediterranean and amber from the Baltic region.
This immense wealth was concentrated among a ruling elite, whose status is visible in the monumental burial mounds surrounding the hillfort. The largest, the Hohmichele mound, is 13 meters high and 80 meters in diameter. In 2010, archaeologists discovered an unlooted grave of a high-status woman dated to 583 BCE. She was buried in a wooden chamber with elaborate gold and amber jewelry, showing the distant trade networks and the sophisticated craftsmanship of the era. To preserve the fragile organic materials, the entire 80-ton block of soil containing the burial was lifted and transported to a laboratory for excavation. Analysis of pottery from the site also shows that imported Mediterranean wine was consumed by all social classes, and the elite.