The Civil Baths of Carnuntum – The Reconstruction of a Roman Public Bath

Public baths were among the central hubs of Roman cities—far beyond their function as facilities for personal hygiene, they were social, communicative, and architecturally outstanding spaces of urban life. Few structures today illustrate this complexity as tangibly as the thermal baths in the Roman quarter of Carnuntum. As one of the most significant monuments of its kind in present-day Austria, it combines technical sophistication, architectural excellence, and social practice into a complex overall picture of Roman bathing culture. At the same time, it exemplifies how archaeological research can develop a coherent understanding of ancient architecture from fragmentary findings.

The excavation site of the Civil City Baths prior to reconstruction - © Land NÖ

The complex is located in the southeastern part of the civilian city, in what is known as Insula VI, where it occupies a central position. Initial excavations took place as early as the 1950s in the former promenade garden of Petronell Castle, and the structure was identified as a thermal bath complex at that time. However, a detailed analysis of its construction history, use, and renovations has only been possible thanks to the investigations conducted since 2001. With an area of approximately 1,800 square meters, the thermal baths are among the largest public buildings in the civilian city and illustrate its distinct urban character during the Imperial period.

Photograph of the thermal baths site showing the earlier partial reconstruction prior to the follow-up investigations in the 2000s - © Land NÖ

The site’s history is remarkable even in its early stages. Traces of an early land division were found beneath what later became the thermal baths, though no evidence of dense residential development was uncovered. This suggests that the site was deliberately kept open for larger-scale public use. The baths were likely constructed during the Hadrianic period in the 2nd century CE, placing them within the context of deliberate urban development and the ongoing monumentalization of the neighborhood. The largest bathhouse in the civilian quarter of Carnuntum, however, was the so-called Forum Bathhouse, which later came to be known locally as the “Palace Ruins”; it too has been archaeologically excavated, but is no longer accessible to the public for conservation reasons.

Reconstructed facade of the thermal baths, including the entrance and thermopolium - © T. Mauerhofer 

The layout of the complex generally follows the classic sequence of Roman bathhouses, yet at the same time exhibits a remarkable degree of differentiation. Access was from the north via a corridor leading into a larger antechamber, the so-called basilica thermarum, which likely also served as an apodyterium. From there, one entered the frigidarium with its cold-water pool and then proceeded to the heated rooms of the tepidarium and caldarium. This central area was supplemented by additional heated rooms, including a sudatorium. This complex layout allowed for flexible use of the facility: by strategically controlling access routes and the sequence of rooms, bath operations could be adapted to different needs and climatic conditions. This adaptability was particularly important in the northwestern provinces.

Newly reconstructed bathhouse rooms at the Zivilstadttherme - © T. Mauerhofer 

The technical infrastructure of the baths is correspondingly complex. Hypocaust heating systems, praefurnia, and a sophisticated water supply and drainage system attest to the considerable planning and construction effort involved. Initially, the complex apparently had a local water supply, including a well and an underground drainage gallery, before it was presumably connected to the municipal water system at a later date. Drainage was also an integral part of the system and included targeted outlets as well as latrines integrated into the hydraulic structure. The thermal baths should thus be understood as a complex technical facility in which water, heat, and usage were precisely coordinated.

The interior decoration underscores the building’s prestigious character. Archaeological findings confirm the presence of wall paintings, marble finishes, and mosaic floors. Particularly striking is a fragment of a ceiling painting in the sala thermarum, which depicts a dancer. Such elements demonstrate that the baths served not only functional purposes but were conceived as a social and aesthetic space in which urban lifestyle and architectural sophistication were manifested.

Painting from the sala thermarum in the Civil Baths depicting a dancer (Inv.-Nr. CAR-W-7) - © Landessammlungen NÖ

Over the course of its use, the complex was repaired and remodeled on several occasions. Repairs to floors, drainage channels, and heating systems, as well as the restoration of adjacent functional rooms following damage, are well documented archaeologically. In late antiquity, however, fundamental changes began to emerge: parts of the heating systems were abandoned, hot water installations were taken out of service, and individual rooms were repurposed. By the 4th century at the latest, the thermal baths had lost their original function as a fully operational bathhouse. Parts of the site were eventually even used as a burial ground, clearly illustrating the profound shift in its use.

Construction work on the thermal baths building in 2010 - © Land NÖ

The modern reconstruction of the baths, completed for the 2011 Lower Austrian Provincial Exhibition, is specifically based on these fragmentary findings. The starting point consists of the floor plan, building structures, technical installations, and evidence regarding furnishings and use, which were combined with typological data from other Roman bath complexes. The reconstruction should therefore not be understood as a free interpretation, but rather as a scientifically grounded approximation of the original structure: where the evidence is clear, it is directly implemented; where there are gaps, plausible additions are made based on archaeological and architectural analogies.

The special quality of the complex lies in this combination of archaeological evidence and interpretive reconstruction. The reconstructed baths serve a dual purpose: they are the result of scientific analysis and, at the same time, a central tool for education. Complex findings are translated into a spatial experience that allows visitors to immediately understand the functioning, use, and significance of a Roman public bath.

Construction work on the thermal baths building in 2010 - © Land NÖ 

The Civilian City Baths of Carnuntum serve as a prime example of how archaeological research does not end with excavation. Only through careful analysis, contextual interpretation, and controlled reconstruction is it possible to make past ways of life visible and understandable once again. As such, they represent not only Roman bathing culture but also the power of modern archaeology to transform ruins back into history.