The Ruins of a Long-Lost Medieval Convent Have Been Discovered Just a Few Feet Beneath a Soccer Field

Clare’s, a convent that operated in eastern Denmark during the Middle Ages. They assumed, however, that all traces of the structure had been lost to history. Locals have been using the land as a soccer field for decades.

But earlier this year, when researchers scanned the site, they were surprised to find that well-preserved ruins survived underground. A ground-penetrating radar (GPR) survey revealed remnants of rooms, cloisters, pillars and a church buried just three feet below the surface. GPR data do not always provide such clear images,” Arne Abel Stamnes, an archaeologist at the Norwegian Institute for Cultural Heritage Research (NIKU), says in a statement.

That’s what prompted ROMU, a Danish museum organization, to partner with NIKU and the National Museum of Denmark to survey the site. In January, researchers drove an ATV across the snow-covered field. The vehicle was equipped with a GPR scanner, a noninvasive tool used to study subterranean structures without disturbing them.

Often, GPR produces images that require extensive processing before useful data emerges. But inside the ATV, as Stamnes watched the images appear on a laptop screen, he immediately realized that the team had made an exciting discovery. Quick fact: What is ground-penetrating radar?

Ground-penetrating radar works by sending radio waves into the earth. These waves bounce off the materials they encounter underground, revealing information about their electromagnetic properties. Clare’s Convent belonged to the Poor Clares, a Roman Catholic order of nuns.

Of the three Poor Clare convents in medieval Denmark, St. Clare’s was the oldest, Søren Steensig notes for the Danish magazine Historie. Clare’s was one of five monastic sites in Roskilde, which emerged as a medieval center of “both ecclesiastical and royal power.” Today, the other four sites are protected monuments.