Massive Roman Bathhouse Spanning Nearly 5,000 Square Meters Unearthed in Netherlands

The Netherlands’ largest Roman bathhouse has been unearthed in Nijmegen, revealing a wealthy urban quarter of Ulpia Noviomagus with heated floors, marble-lined pools, luxury homes, and tens of thousands of Roman finds.

The discovery was made during excavations in the Waalfront district, a former industrial zone now being prepared for new housing. Archaeologists from RAAP and BAAC, working under the management of The Missing Link, have exposed a large part of a public bath complex that belonged to Ulpia Noviomagus, the Roman city that once stood along the Waal River in what is now Nijmegen.

The excavations began in September and are scheduled to continue until July. According to Gemeente Nijmegen, the remains form the largest Roman-period bathhouse complex so far documented in the Netherlands.

A Roman bathhouse on an exceptional scale

The newly documented complex covers at least 4,900 square meters. That makes it more than twice the size of the public bathhouses previously investigated at Forum Hadriani, near present-day Voorburg, and Coriovallum, modern Heerlen.

Such a large bathing complex was not simply a place to wash. In Roman cities, public baths were part of everyday social life. Citizens met there, conducted conversations, relaxed, exercised, and moved between heated, warm, and cold rooms. In Nijmegen, the scale of the thermen suggests a city with the resources, population, and civic ambition to support monumental public architecture.

Part of the bathhouse had already been found in 1992 during the expansion of the Honig factory, but only a limited section could be examined at that time. The current excavation has added a new sequence of rooms, including areas associated with hot, warm, and cold baths. Archaeologists believe these spaces were added during a later phase of the complex.

It is still unclear whether all parts of the bathhouse were in use at the same time. One possibility is that the expansion replaced older bathing rooms. Another is that a new wing was added, perhaps to create separate bathing areas for men and women.

Heated floors, marble pools, and painted walls

Despite later damage, parts of the bathhouse are remarkably well preserved. The complex was used as a source of building stone in the Middle Ages and later periods, which explains why many walls were dismantled. Even so, large sections of the drainage system and floors remain intact.

One of the clearest signs of Roman engineering is a concrete floor preserved with small brick pillars from a hypocaust, the underfloor heating system used to circulate hot air beneath rooms and pools. Two-stone foundations still stand up to two meters high. Gemeente Nijmegen describes them as among the best-preserved Roman masonry remains in the city.

The construction materials point to a building with a costly and carefully designed interior. The inner walls of the pools were clad in marble. Floors were made with black and white limestone tiles. Other rooms had brightly painted plaster, while façades included decorative moldings of limestone and sandstone. Columns of limestone and sandstone were also used in the bath buildings.

For a Roman city on the northern frontier of the empire, this was not modest architecture. It was a public statement in stone, color, and heat.

Bacchus, jewelry, and hundreds of bone hairpins

The finds from the excavation add a more intimate layer to the story. Tens of thousands of objects have been recovered from the site, including coins, jewelry, signet rings, fragments of bronze statues, and a necklace with a gold clasp.

Among the most striking discoveries is a bronze bust of Bacchus, the Roman god of wine. The object was originally part of a pouring vessel or a piece of furniture, but it was later modified with an eyelet so it could be used as part of a weighing scale.

Archaeologists also found hundreds of bone hairpins. These were used in the elaborate hairstyles worn by Roman women. Two examples are decorated with cat figures, one seated and one standing. Details like these move the discovery beyond architecture. They show how fashion, status, and domestic life were woven into the urban culture of Roman Nijmegen.

The finds suggest that residents of this part of Nijmegen-West lived in considerable comfort about 1,800 to 1,900 years ago.

Ulpia Noviomagus and the Roman city on the Waal

Nijmegen has one of the deepest Roman histories in the Netherlands. The Roman settlement on the Waal developed into Ulpia Noviomagus, a major urban center linked to the military and economic life of the Lower Rhine frontier.

The city is generally understood to have received municipal status around AD 100 under Emperor Marcus Ulpius Traianus, better known as Trajan. Its name preserved the emperor’s family name, Ulpius, while Noviomagus is commonly understood as “new market.”

Ulpia Noviomagus was more than a local settlement. Its position near the Waal made it important for transport, supply, and administration along the Roman frontier. By the late 2nd century, the city covered roughly 600 by 600 meters and may have had between 5,000 and 7,000 inhabitants. Monumental public buildings stood close to the river, including temples, a forum area, and the large public bathhouse now being exposed in greater detail.

The latest excavation therefore does more than enlarge the known footprint of the baths. It helps reconstruct the character of a Roman city that functioned as a civic, commercial, and cultural center in the northern provinces.

Coins point to life deep into the 3rd century

One of the more important historical results is chronological. The excavation shows that this part of Ulpia Noviomagus remained active well into the 3rd century AD.

That conclusion is supported especially by the many coins of Emperor Postumus, who ruled from AD 260 to 269, along with coins of his immediate predecessors and successors. Finds from this period are rare elsewhere in the Roman city, which makes the Waalfront evidence particularly valuable.

Postumus ruled the breakaway Gallic Empire, a political formation that emerged during a period of crisis on the Roman frontiers. The presence of his coinage in this sector of Nijmegen suggests that urban life did not simply fade away early in the century. At least in this quarter, the baths and riverside buildings remained in use longer than previously assumed.

A Roman past beneath a future neighborhood

The excavation site is part of a new residential development by BPD | Bouwfonds Gebiedsontwikkeling. The city says several parts of the Roman remains will be preserved in place, and plans are being developed to make the surviving walls visible beneath the new construction.

The future neighborhood will also refer to the Roman past in its design. Some residential buildings are expected to include covered walkways with rows of columns, recalling a colonnade. The green square at the center of the development will be named Thermenplein, or “Baths Square,” after the Roman meeting place that once stood there.

Some of the finds from the excavation will go on public display from June 29 in a showcase in the lobby of Nijmegen City Hall.

For Nijmegen, the discovery adds a substantial new piece to a long archaeological record. For Roman archaeology in the Netherlands, it gives clearer shape to the scale and sophistication of Ulpia Noviomagus, a city where frontier life could include marble-lined baths, heated floors, bronze art, and the daily rituals of urban comfort.

Gemeente Nijmegen (Municipality of Nijmegen)

Cover Image Credit: Gemeente Nijmegen (Municipality of Nijmegen)