The Heuneburg is a prehistoric Celtic hillfort by the river Danube in Hundersingen near Herbertingen, between Ulm and Sigmaringen, Baden-Württemberg, in the south of Germany, close to the modern borders with Switzerland and Austria.

It is considered to be one of the most important early Celtic centres in Central Europe, particularly during the Iron Age Hallstatt culture period.

During the Iron Age the Heuneburg is thought to have controlled a surrounding area of over 1,000 km2 (390 sq mi) including other hilltop settlements, hamlets, villages, roads, cemeteries and cult or gathering places.

[1][2] ..."The Istros river arises among the Celts and the polis of Pyrene, cutting Europe across the middle" — Herodotus (c.484–c.425 BC).

[7] Since 2003, the Heuneburg is one of the foci of a multi-disciplinary research project on early Celtic centres undertaken by the Deutsche Forschungsgemeinschaft.

[6] Although best known for its role as an important early Celtic centre from the 7th to 5th centuries BC, the Heuneburg was occupied at several other points during its history.

The first settlement on the site dates to the Middle Bronze Age (15th to 12th century BC) during the Tumulus culture period.

[6] The citadel was reoccupied and refortified around 700 BC; adjacent areas were occupied at the same time, including Alte Burg and Grosse Heuneburg.

The Heuneburg complex developed briskly, and by 600 BC, it was one of the key centres of power and trade in Celtic/Halstatt Southern Germany.

It used to be assumed that the Heuneburg was abandoned by the La Tène period, but recent evidence does not fully support this view.

[10] The main two-hectare (4.9-acre) plateau on the mountain spur, 40m above the Danube and naturally defensible, was the centre of high-status occupation and of fortification in Celtic periods.

A limestone foundation supported a sun-dried mudbrick wall of c. 4 m (13 ft) height, probably topped by a roofed walkway, thus reaching a total height of 6 m. The wall was clad with bright white lime plaster, regularly renewed; this was necessary to prevent the northern weather from eroding the unbaked mudbrick.

[14] The fortification had two monumental gates, one to the west, giving access to the outer settlements, and another to the east, probably to a steep road leading directly to the Danube (and perhaps a harbour).

[17] The Heuneburg yielded many finds marking it as a rich site, operating both as a local centre of production and as a hub for long-distance trade.

These included a full bronze workshop, a high proportion of Greek vases (in fact, the fragments make up about a dozen Greek pots, indicating a larger amount than contemporary sites but also a very limited elite access to such material), and other imported raw materials like tin and amber.

It appears to have consisted of separate fenced or palisaded lots, each containing a main dwelling, storage areas and much terrain for fields.

A triple system of several hundred metres of banks and ditches enclosed and subdivided the lower terrain just west of the Heuneburg proper.

It had been robbed in antiquity, but modern archeological finds nevertheless included weapons, gold and bronze attachments for garments, and some amber plaques that probably once adorned a kline (couch) imported from the Mediterranean.

A cluster or necropolis of burial mounds, the so-called Hohmichele Group, is located 3.5 km (2.2 mi) west of the Heuneburg.

The first excavation of the main Hohmichele mound took place from 1936 to 1938, directed by Gustav Riek as part of the research programme of the SS-Ahnenerbe.

Its occupant was a woman who had died between 18 and 30 years of age, her remains accompanied by two bronze armlets and over 20 pottery vessels with incised and stamped decorations and red paint.

There can be no doubt that the Heuneburg and its associated monuments are one of the most important centres of the early Celtic Iron Age in Central Europe.

[25] A growing differentiation in terms of wealth that is visible among settlements sites but especially among burials, indicates the development of social hierarchies.

The traditional term Fürstensitz ("princely seat") to describe sites like Heuneburg has been criticised recently, especially by the archaeologist Manfred Eggert (University of Tübingen).

It remains likely that the mudbrick fortification was indeed destroyed violently, but there is no exact evidence to indicate whether this may have been the result of external warfare or of internal difficulties.

[25] It has been proposed that the flourishing of Celtic cultures between the 7th and 5th centuries BC is connected with a warm phase that coincided with that period.

A milder climate would have permitted more successful agriculture, which would, in turn, have allowed for larger populations, and thus for the development of more complex political, social and artisanal specialisations.

Placed just north of the Alps and on the Danube, the site had access to important land routes across the mountains from Italy and Southern France (especially the Greek colony of Massalia), and, by river, to the Balkans and the Black Sea.

[25] The Mediterranean (Greek and/or Etruscan) influence on the Heuneburg is especially strongly reflected by its mudbrick fortification and the newly found ashlar masonry.

[28] In the mid-5th century BC, the Greek historian Herodotus (Book 2.33) made a brief passing reference to a Celtic city called by the Greek "Pyrene": "For the Ister flows from the land of the Celts and the city of Pyrene through the very middle of Europe..." Since the Heuneburg is roughly in the right location and was a major regional centre just before that time, it is possible that it is the settlement referred to by that name.