Hundreds of medieval skeletons lie beneath the floor of a Paris supermarket.

More than 200 skeletons were unearthed in mass graves beneath a supermarket in Paris, which had once been the ancient cemetery of Trinity Hospital in the 13th century.

A mass grave containing over 150 people was found at the site. Photo: Live Science

To date, archaeologists have discovered approximately eight burial pits. Seven pits contained between 5 and 20 people, while the remaining pit contained over 150. All showed no obvious signs of injury or disease. The skeletons were arranged vertically from head to toe.

Although the exact cause of death of these individuals is unknown, this remains hoard could help uncover how medieval people buried the dead during famines or epidemics, researchers say.

To track their movements, the research team plans to use radiocarbon dating to estimate when these individuals lived. By combining this data with medieval Parisian texts and maps, the researchers hope to uncover the cause and timing of their deaths.

According to Live Science, the mass graves were discovered during renovations of the basement of the Monoprix Réaumur-Sébastopol supermarket in Paris. When workers excavated the ground, they found numerous skeletons of men, women, and children neatly arranged.

The site was formerly the location of Trinity Hospital, founded in 1202 by two German nobles. In 1353, during the Black Death pandemic, the hospital opened a cemetery, providing a lucrative service for its administrators at the time.

During the devastating pandemic, hundreds of people died each day at the Hôtel-Dieu de Paris – the city's oldest hospital – and it was difficult to find enough burial space in the crowded city. Sometimes, bodies were transported to be buried at the Trinity Hospital Cemetery.

In the 1500s, Trinity Hospital was converted into an apprenticeship center for young children. By the 1700s, it began to fall into disrepair. During the French Revolution, the hospital was demolished, and the remaining buildings were converted into animal shelters.

According to VnExpress