Mols does not carry out the excavations himself; this is done by archaeologists from the research agencies RAAP and BAAC. However, the Radboud researcher does keep a close eye on the excavations. Based at Radboud University, Mols and his team are working together with the archaeologists and the Valkhof Museum to gain a better understanding of Roman Nijmegen, Ulpia Noviomagus.
The excavations began in September last year and will continue until the end of July this year. The finds have been made at a new-build site developed by BPD | Bouwfonds Gebiedsontwikkeling. In addition to the bathhouse, adjacent blocks of houses with streets running between them, luxurious townhouses and a tower have been discovered. There have also been many remarkable finds, such as hairpins, jewellery, coins and a bronze bust of Bacchus, the Roman god of wine.
Historic bathhouse complex
‘A bathhouse was an integral part of a Roman town,’ says Mols. ‘During the excavations, we only see the lower parts of the buildings, often the foundations or sometimes just the spot where they once stood. But from this we can deduce just how large and imposing this bathhouse complex must have been in 3D. This shows that Roman Nijmegen was a city of considerable stature, well into the third century.’ With a floor area of at least 4,900 m², the entire bathhouse complex at Ulpia Noviomagus was certainly twice as large as the previously investigated public bathhouses of the Roman towns of Forum Hadriani (2,200 m², Voorburg near The Hague) and Coriovallum (2,500 m², Heerlen).
Part of the bathhouse had already been discovered in 1992. At that time, only a relatively small section could be investigated. It is believed that the Roman settlement on the River Waal in what is now Nijmegen-West was granted city rights by Emperor Marcus Ulpius Trajanus around the year 100 AD and that, shortly afterwards, a number of large public buildings were erected using natural stone. One of these was the public bathhouse. The excavation reveals that costly building materials were used, such as marble, limestone and sandstone. The complex was used as a quarry during the Middle Ages and thereafter, resulting in the demolition of many of the walls. However, large sections of the drainage channels and floors remain intact, including a concrete floor topped with small brick pillars from a hypocaust, the Roman underfloor heating system.
State-of-the-art technology
‘If you’d been walking around here back then, you wouldn’t have got the impression that you were on the edge of the Roman Empire, such was the luxury and scale of the buildings,’ says Mols. ‘The Romans didn’t regard this city as a backwater. There were a lot of soldiers here. When they weren’t fighting, they needed something to keep them occupied, so they built complexes like this.’
Mols and his colleagues want to investigate the technology used in the bathhouse, for example in the underfloor and wall heating systems. Mols: ‘We can still learn a thing or two from that today. The same applies to the mortar – Roman concrete – which was self-healing: if it cracked, it could repair itself. Knowledge of this is also very useful for scientific research into self-healing materials.’