Medieval Cannonballs Found Beneath Future Administrative Centre in Belgium’s Nieuwpoort

A future civic building in Nieuwpoort has unexpectedly opened a window onto the Belgian city’s defensive past. Archaeologists working on the site of the planned Administrative Centre have uncovered a depot of natural-stone cannonballs, medieval building traces and a First World War shell, showing how one urban plot carried strategic meaning across several centuries.

The excavation area lies in Nieuwpoort-Stad, between the historic Stadshalle and Willem De Roolaan. Fieldwork began in mid-February 2026 after earlier test trenches and trial pits showed strong archaeological potential. The site is now approaching the end of its fieldwork phase, but the discoveries already suggest that this part of Nieuwpoort was more than an ordinary urban zone. It stood close to the town’s medieval civic heart and near the former southern city wall, a position linked to both administration and defence.

A medieval arsenal beneath the city

The most eye-catching find is a hoard of dozens of cannonballs made from natural stone. Such projectiles were used in Europe between about 1350 and 1600, a period when warfare was shifting from older mechanical siege engines to gunpowder artillery. Stone balls could be launched from early cannon, catapults or trebuchets. In Nieuwpoort, however, their careful finish and high level of standardization point strongly toward their use with firearms.

That detail matters. Standardized ammunition suggests planning, storage and military organization. The variation in size also indicates that the city may have held a mixed arsenal, suited to more than one type of weapon. Rather than a random collection of stones, the depot looks like a prepared stock of military material.

For now, archaeologists are cautious about why the cannonballs were buried together. Their location offers one important clue. The excavation site stands near the line of the vanished medieval southern city wall, now associated with Willem De Roolaan. A 1641 map by Antonius Sanderus shows a cannon in the area of the city wall, close to the present excavation zone. That does not prove a direct link with the newly discovered depot, but it gives researchers a promising historical lead to test.

Medieval traces near the Stadshalle and belfry

The cannonballs were not the only medieval evidence found. Excavators also documented soil features, walls and floor levels. These remains are important because they were found in the shadow of the Stadshalle and belfry, a civic complex that has shaped Nieuwpoort’s urban identity since the thirteenth century. Although the traces appear to date from after the construction of the belfry, they may help clarify how the surrounding area developed over time.

Their exact function remains unknown. They could relate to buildings, yards, working spaces or infrastructure connected with the town’s fortified landscape. Detailed analysis of the finds, soil layers and dating evidence will be needed before archaeologists can understand how these structures fit into Nieuwpoort’s medieval topography.

A First World War reminder

The excavation also produced a more recent and dangerous reminder of the city’s past. An unexploded shell from the First World War was found during the work. Belgium’s explosive ordnance disposal service, DOVO, was called to secure and remove the munition. The find underlines Nieuwpoort’s role as a front-line city during the 1914–1918 conflict, when the city suffered severe destruction.

Seen together, the finds create a layered portrait of Nieuwpoort as a city repeatedly shaped by defence, damage and reconstruction. The medieval cannonballs point to an era of walls, artillery and urban protection. The First World War shell recalls a modern conflict that devastated the same landscape centuries later. Between them lies the long story of a coastal city that had to defend its people, its civic centre and its place in a contested region.

Local officials have emphasized the symbolic value of the discovery. Heritage alderman Ann Gheeraert said the finds exceeded expectations, ranging from medieval structures to an exceptional cannonball depot and military relics connected to Nieuwpoort’s past as a front-line city. Mayor Kris Vandecasteele noted that the discoveries show how history remains present just a few meters beneath the surface.

What happens next

The next stage will be crucial. Once fieldwork ends, specialists will begin a full research and reporting phase. The cannonballs, architectural remains and other materials will be studied before final conclusions are drawn. For Nieuwpoort, the timing is striking. The city hopes to lay the first stone of its new Administrative Centre by the end of 2026. Before that future building rises, the ground beneath it has delivered a powerful reminder: civic life in Nieuwpoort has always stood close to protection, resilience and memory.

City of Nieuwpoort

Cover Image Credit: City of Nieuwpoort