Get the Popular Science daily newsletter💡 Breakthroughs, discoveries, and DIY tips sent six days a week. Renovations on government buildings in the coastal Belgian town of Nieuwpoort are currently on hold after surveyors discovered an impressive archaeological trove: dozens of carefully crafted stone cannonballs dating as far back as the 14th century. However, the medieval ammunition backstock wasn’t the only weaponry buried roughly 70 miles west of Brussels. According to city officials, experts also excavated an unexploded artillery shell from World War I. “What has been exposed here in recent weeks proves that Nieuwpoort is a city where history is literally everywhere. Even a few meters under our feet,” Nieuwpoort Mayor Kris Vandecasteele said in a statement. Investigations into the small plot of land began in February, after preliminary test digs indicated promising archaeological relics in the area. Since then, excavations have yielded numerous stone cannonballs near the site of what was once the city’s southern fortification wall. Researchers say that the carefully assembled stockpile and its location suggest it was an intentional store of …