Dozens of Medieval Cannonballs Unearthed Beneath a Belgian City’s Walls

Dozens of medieval cannonballs, buried together in a tight concentration beneath a Belgian city street, have just been pulled from the ground — and they’re rewriting what historians thought they knew about one of Flanders’ oldest fortified towns.

Archaeological excavations in Nieuwpoort, a coastal city in Belgium, have uncovered a remarkable hoard of natural stone cannonballs alongside structural remains and other artefacts that offer a rare window into the city’s medieval past. The finds were made during investigations ahead of the construction of a new Administrative Centre, turning what might have been a routine building project into one of the most significant local archaeological discoveries in recent memory.

Work began in mid-February 2026 on a site positioned between the Stadshalle and Willem De Roolaan, close to Nieuwpoort’s historic centre — and the ground, it turns out, had a great deal to say.

What Archaeologists Actually Found Beneath Nieuwpoort

The excavation site sits near the very heart of medieval Nieuwpoort, not far from where the city hall and belfry have stood since the thirteenth century. That location alone made archaeologists pay close attention. But what they found exceeded expectations.

Researchers identified multiple soil traces dating to the Middle Ages, as well as walls and floor levels pointing to previously unknown structures. These aren’t minor traces — they suggest entire buildings or complexes that have gone unrecorded until now. The exact function of these structures hasn’t been determined yet, but further analysis and dating work is expected to clarify how they fit into the broader medieval urban landscape.

And then there are the cannonballs.

The most striking find is a concentrated hoard of natural stone cannonballs — numbering in the dozens — buried together in one location on the site. These weren’t scattered randomly. They were grouped, which suggests deliberate storage or stockpiling rather than battlefield debris. According to archaeologists, this type of stone projectile was commonly used between approximately 1350 and 1600, placing them squarely in the late medieval and early modern period when Nieuwpoort would have been a fortified settlement of genuine military significance.

The Medieval Cannonballs: Key Facts at a Glance

To put the discovery in context, here’s what has been confirmed so far from the excavation:

• The site had already shown archaeological potential through earlier test trench investigations before full excavations began.
• The cannonballs were found in a concentrated hoard — not scattered — suggesting deliberate storage.
• The structural remains point to previously unknown medieval buildings in this part of the city.
• Archaeologists have not yet determined the precise function of the uncovered structures.

Why This Find Matters Beyond the History Books

Nieuwpoort is already known as a historically significant town. Founded in the twelfth century, it played a role in Flemish trade and military affairs throughout the medieval period. But discoveries like this one push that understanding further — and in unexpected directions.

A concentrated hoard of cannonballs doesn’t just confirm that Nieuwpoort had defences. It raises sharper questions: Were these projectiles stockpiled in anticipation of a siege? Were they part of an organised arsenal maintained by the town? The grouping suggests planning and military organisation, not the chaos of an active battlefield.

The structural remains add another layer. Walls and floor levels from the Middle Ages that weren’t previously known to exist mean that the map of medieval Nieuwpoort may need to be redrawn. Urban archaeology like this often fills in the gaps that written records leave behind — and in this case, the gaps appear to be significant.

For residents of Nieuwpoort, the finds offer something more immediate: a tangible connection to the city’s origins. The site being excavated is in the heart of the modern city, steps from landmarks that have defined the town for centuries. The medieval and the contemporary are, quite literally, layered on top of each other.

What Happens Next With the Excavation

The excavation is ongoing, and archaeologists have been clear that much of the interpretive work still lies ahead. The structures uncovered need to be dated more precisely, and their relationship to the surrounding medieval urban landscape needs to be established through further analysis.

The cannonballs themselves will require detailed study — examining their size, stone type, and manufacturing characteristics could help narrow down their origin and intended use. Comparative analysis with similar finds from other Flemish sites may also help place them in a wider regional military context.

As for the construction project that triggered the dig — the new Administrative Centre — that work remains on hold in the excavation zone while archaeologists complete their investigations. The earlier test trenches that flagged the site’s potential have clearly proven their worth. What began as a precautionary archaeological check has turned into something considerably more significant.

Archaeologists have noted that while the discoveries are striking, it is still too early to draw firm conclusions about the full scope of what lies beneath the surface. Further excavation and laboratory analysis will determine how much more the site has to reveal.

Frequently Asked Questions

Where exactly were the medieval cannonballs found?
They were discovered during excavations on a site between the Stadshalle and Willem De Roolaan in Nieuwpoort, Belgium, close to the city’s historic centre.

How many cannonballs were uncovered?
Archaeologists found dozens of natural stone cannonballs buried together in a concentrated hoard. An exact count has not yet been published.

How old are the cannonballs?
This type of natural stone projectile was commonly used between approximately 1350 and 1600, placing them in the late medieval to early modern period.

Why were excavations being carried out in Nieuwpoort?
The excavations were triggered by plans to construct a new Administrative Centre in the area. Earlier test trench investigations had already indicated significant archaeological potential at the site.

What other discoveries were made alongside the cannonballs?
Archaeologists also uncovered walls, floor levels, and soil traces dating to the Middle Ages, suggesting the existence of previously unknown medieval structures in that part of the city.

Have the structures found at the site been identified?
Not yet. Archaeologists have confirmed the presence of walls and floor levels but say it is too early to determine the exact function of the structures. Further analysis and dating work is ongoing.