The main 2-hectare 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.
It measures only 150 by 300m but is the main visual landmark in the area.
From circa 700 BC onwards, it was the centre of a large settlement.

The main settlement on the citadel underwent several changes during its existence.
As the houses were built of wood and daub, and the fortifications mostly of wood and earth, they were replaced frequently.
This resulted in over a dozen identifiable occupation phases, representing at least 250 years of activity.

The plateau was refortified from circa 700 BC onwards.
Originally, the fortification took the form of a classic Celtic wood-and-earth wall (murus gallicus), replaced regularly.

Around 600 BC, this was replaced by a structure without parallel in contemporary Celtic Europe.
A limestone foundation supported a sun-dried mudbrick wall of circa 4 m 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.
 Towers protruded outwards from the wall at intervals.
It must have been widely visible in the area, as the modern reconstruction of a section is.
 No other mudbrick structures are known from Celtic Central Europe at this time.
It is generally accepted that this structure imitated contemporary walls in the Mediterranean region.
  
The wall lasted circa 70 years (much longer than its wood-and-earth predecessors and successors which had to be renewed frequently).
After a fiery destruction around 530 BC, the settlement was defended by a murus gallicus again until a further destruction in the 5th century.

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).

The citadel contained a regular system of streets and houses.
It appears that the settlement underwent a major reorganisation after 600 BC, after which the dwellings were much more densely and regularly spaced than before.
At all times, the Heuneburg houses are of remarkably large size and elaboration compared to contemporary settlements.
The uniform buildings probably served as dwellings and workshops.
There is evidence for an active metal industry, including a bronze workshop in the southeast corner of the citadel.

After the 530 BC destruction of the mudbrick wall, the internal arrangements underwent some changes.
The workshops were moved to the north.
A very large house (14 by 30 m) was built in the southeast corner.
This is sometimes interpreted as a Herrenhaus, i.e. the dwelling of a local ruler.

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.
Much of the exotic material dates from after 530 BC.
There was also a local tradition of producing painted and decorated (incised or stamped) pottery.
The main 2-hectare 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. It measures only 150 by 300m but is the main visual landmark in the area. From circa 700 BC onwards, it was the centre of a large settlement.
The main settlement on the citadel underwent several changes during its existence. As the houses were built of wood and daub, and the fortifications mostly of wood and earth, they were replaced frequently. This resulted in over a dozen identifiable occupation phases, representing at least 250 years of activity.
The plateau was refortified from circa 700 BC onwards. Originally, the fortification took the form of a classic Celtic wood-and-earth wall (murus gallicus), replaced regularly.
Around 600 BC, this was replaced by a structure without parallel in contemporary Celtic Europe. A limestone foundation supported a sun-dried mudbrick wall of circa 4 m 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.  Towers protruded outwards from the wall at intervals. It must have been widely visible in the area, as the modern reconstruction of a section is.  No other mudbrick structures are known from Celtic Central Europe at this time. It is generally accepted that this structure imitated contemporary walls in the Mediterranean region.   
The wall lasted circa 70 years (much longer than its wood-and-earth predecessors and successors which had to be renewed frequently). After a fiery destruction around 530 BC, the settlement was defended by a murus gallicus again until a further destruction in the 5th century.
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).
The citadel contained a regular system of streets and houses. It appears that the settlement underwent a major reorganisation after 600 BC, after which the dwellings were much more densely and regularly spaced than before. At all times, the Heuneburg houses are of remarkably large size and elaboration compared to contemporary settlements. The uniform buildings probably served as dwellings and workshops. There is evidence for an active metal industry, including a bronze workshop in the southeast corner of the citadel.
After the 530 BC destruction of the mudbrick wall, the internal arrangements underwent some changes. The workshops were moved to the north. A very large house (14 by 30 m) was built in the southeast corner. This is sometimes interpreted as a Herrenhaus, i.e. the dwelling of a local ruler.
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. Much of the exotic material dates from after 530 BC. There was also a local tradition of producing painted and decorated (incised or stamped) pottery.
Heuneburg