The 3D reconstruction of the Heidentor
The authentic reproduction of the Heidentor, as it was originally constructed in the 4th century AD
As part of the project “Twin it! – 3D for Europe’s culture”, the State Collections of Lower Austria digitised the Heidentor of Carnuntum, emblematic of Roman Austria, in 3D. In addition to the contemporary view, a reconstruction of the Heidentor was created based on historical views and scientific knowledge, illustrating how it might have appeared at its time of origin in the 4th century.
The quadrifrons and its materials
Originally, the Heidentor was a so-called quadrifrons, a construction with four pillars connected by four archways. At its centre, a robustly constructed round pedestal still stands today, which likely supported a life-size statue of the emperor in ancient times.
The Heidentor was constructed during the Late Roman Antiquity, likely during the reign of Emperor Constantius II (351–361 AD). It measured approximately 14.5 metres in both length and height. Above the arches was the attic zone adorned with columns, brackets, marble sculptures, and inscription panels.
The core of the four pillars was made of Roman concrete and rubble, while the outer shell comprised large ashlar blocks and brick masonry.
The roof finish in the current 3D model of the reconstruction has been designed with a pyramidal top. As early as 1769, Matthias Fuhrmann had considered the possibility of a flat roof crowned with figures.
Pyramid or flat roof?
After Josef Dell reconstructed a towering pyramid roof in 1904, a flat roof was reconsidered in the 1980s. Later, this notion continued, but a gently sloping roof could also have been possible.
The pedestal and marble figures
In the centre of the archways stood a pedestal, which likely supported a golden or gilded life-size statue of the emperor. Due to the dating, this statue was probably of Constantius II. The golden emperor statue on the round pedestal was specifically created for the 3D reconstruction of the Heidentor to give an impression of how the statue might have looked in the overall view.
The cross vault in the middle of the arch passageways was plastered and adorned with wall paintings.
In the niches of the attic zone stood marble figures, as suggested by some fragments found. Apart from some heavily fragmented inscription remains, these figure fragments were the only indications of the use of marble.
What is an attic zone?
The drawn 3D model
To create a 3D model from a 2D template, the components are designed digitally in a detailed drawing process and individually integrated into the model. This process required close coordination between the technical draughtsman and archaeologists. Their collaborative efforts focus on accurately representing features such as the surface structure, the attic zone, the roof design, and also the cornices. The goal is to ensure that the elements are executed in line with current research on the reconstruction of the Roman model.