This may sound like the opening to some sort of murder mystery or horror movie, but it is not an unknown phenomenon. For instance, in 2023, the owner of a house in the Montconseil district of Corbeil-Essonnes, France, made just such a grisly discovery while renovating their basement. During the initial work on the four-room basement, the homeowner unearthed a skeleton that had been hidden below the ground for years. Was this basement now a crime scene or something else?

Initially, analysis suggested the body was indeed pretty old and potentially related to other bodies that have been discovered in the area since the 19^th century. It turns out there is a local medieval graveyard nearby connected to the Notre-Dame-des-Champs chapel, which was built in the seventh century above a Pagan temple dedicated to the Roman god Mercury. So, this skeleton must have been one of those, right? Well as excavation work continued, the situation became even more intriguing.

In the end, the archaeologists who investigated the site unearthed an additional 37 skeletons and 10 plaster sarcophagi. What’s more, the bodies appeared to be far older than previously suspected; the first burial dates from late Antiquity – more than 1,500 years ago and much older than the chapel.

The case of the bodies found at Corbeil-Essonnes is not as unusual as you may think. Across the world, as people renovate homes or expand urban spaces, the living come into contact with the forgotten remains of the dead. Sometimes the unearthed bodies are relatively “new”, having only been in the ground for a century or two – such as in major US cities, like Chicago, Milwaukee, New York, and Philadelphia – while others are much older. Here’s a list of such sites that have offered us rare insights into worlds and lives that are long gone.

Returning to Corbeil-Essonnes

Before expanding into important examples of accidentally discovered graves, we’re not quite done with the burial site in France.

The bodies discovered here were arranged in parallel rows, despite the site having several rocky outcrops. This way of laying the dead to rest was used between the third and 10^th centuries CE. The older remains were also found lying on their backs, usually in wooden coffins laid in a deep grave. This method of burying the dead remained in practice until the start of the medieval period, when funerary practices shifted to placing people in plaster sarcophagi – which was common on the Île-de-France at the time.

Sometimes this type of sarcophagi would have decorated exterior sides, but this was not the case with the ones found in Corbeil. They also tended to only contain the remains of one person – which is unusual as such sarcophagi often contained several bodies – placed side-by-side in a fan shape that shifted slightly to the east as it progressed.

There was also one sarcophagus that had a block of soft stone placed on top of it, which had been cut and sculpted. However, the block is not complete, so researchers are not sure exactly what it was meant to be.

“However, part of a rose window can be distinguished, while the opposite face has a Latin cross and a cross inscribed in a circle,” Archeodunum explained in a translated statement.

These motifs are quite common on plaster sarcophagi, evoking features that appear on the facades of Christian churches.

The bodies discovered at Corbeil-Essonnes are now undergoing further analysis as researchers attempt to identify the sex of the individuals buried there, how old they were when they died, and how they may have lived. It is hoped that this work will tell us more about how the population lived during this period of France’s history, but also how funerary practices evolved from late Antiquity into the Middle Ages.

Plague pits of London

When it comes to rediscovering long-forgotten graves, there are few places that can boast the macabre and chilling history of London. For below its busy, convoluted streets, below even the subterranean world of the London Underground, are the remains of unknown multitudes who lost their lives to disease and now lie together in mass graves.

Between 1664 and 1665, the Great Plague hit London and claimed around 100,000 lives, almost a quarter of the city’s population at the time. During the early stages of the outbreak, victims were buried within the consecrated grounds of their local parish, but as time wore on and the numbers of the dead rose, the graveyards became full. At its peak, many people who died were buried in communal pits, often without ceremony or any memorialization. These pits were usually dug in the surrounding fields, such as in Soho, Bunhill, and Bedlam, and then filled in once they were full.

This may sound like cruel treatment of the hapless victims of a terrible disease, but at a time when the culture still emphasized the importance of a Christian burial, this was a demonstration of just how desperate things were. The decision to use mass pits was also driven by the need to quickly dispose of the bodies to stop the infection from spreading, especially during the heat of the summer months.

After the plague passed, the pits were left undisturbed and then became forgotten as the city grew. Now, they rest under the sprawling city where they are rediscovered from time to time when the foundations for new buildings are built or when train lines are laid down.

For instance, in 2015, construction workers found the remains of 40 plague victims in a mass grave at Liverpool Street, while working on the cross-London Crossrail line. The site was originally part of the Bedlam cemetery (near the (in)famous Bethlehem, or “Bedlam” hospital), which was used from 1569 to around the mid-1700s. While recovering the bodies, archaeologists found a grave marker with the date of 1665 recorded on it, which situates the bodies right within the time of the Great Plague.

Subsequent DNA analysis on teeth samples, conducted by the Museum of London Archaeology (MOLA), confirmed the victims had indeed contracted bubonic plague while still alive – a disease that is still present in the world today and is caused by the bacterium Yersinia pestis.

It has typically been assumed that the bodies in plague pits were simply thrown in, but those recovered from the Bedlam grounds had all been placed in wooden coffins and organized in neat rows.

“Some historical accounts of the period talk about how people were haphazardly thrown into burial pits during the plague, but our archaeological evidence didn’t support that. It seemed bodies were buried in a decent and proper manner, even at a time of a big and catastrophic event like the plague,” Michael Henderson, a senior human osteologist at MOLA told Express.co.uk in 2022.

African burial grounds in New York City

The discovery of long lost or unmarked graves such as plague pits or ancient burial sites found in domestic residencies can tell us much about how people lived or dealt with significant events (like an epidemic) in the past, but sometimes they also remind us of more uncomfortable aspects of history.

In 1991, New York’s General Services Administration (GSA) began construction of a 34-story federal office tower on 290 Broadway. As part of the construction process, archaeologists assisted with determining whether there were any potential archaeological and cultural features at the site that could have been of significance. 

During the preliminary excavation, researchers found intact skeletons buried 9 meters (30 feet) below the city street level. The remains were part of the forgotten “Negroes Buriel Ground” – a 6-acre (2.4-hectare) funerary site that contained the intact skeletons of 15,000 enslaved and free Africans who had lived, worked, and died in colonial New York.

The burial ground was used between the mid-1600s and 1795 and is currently recognized as the US’s earliest and largest African burial ground rediscovered to date. The discovery had significant impacts on the historical understanding of enslavement and its role in New York City.

There is a thoughtful overview of this burial site’s history provided by Christopher Moore, a descendent of Groot Manuel, one of the first enslaved Africans in New York City. The account not only describes the history of enslavement in New York, but also how these often-unrepresented historical actors contributed to its construction and early life.

According to Moore’s piece, the African population was largely shut out of churchyards in the city, so a burial ground was developed for them on land that rested outside of the city in the 1670s (though the exact date that the cemetery was founded remains unknown). The land was owned by Sara Van Borsum, a Dutch interpreter and slave owner whose family continued to offer approval for the cemetery’s use until it closed in the late 18^th century.

Although the enslaved people were allowed to carry out traditional funerary practices to a certain extent, there were significant strict legal restrictions that impacted them. For one thing, funeral processions were limited to 12 people maximum, and internment and graveside activities were forbidden at night – which was a customary time for many African traditions. At the same time, enslaved Black people were also expected to carry a written pass that allowed them to travel more than a mile away from their homes.

“For many,” Moore wrote, “that was about the distance from their Lower Manhattan homes to the cemetery.”

The burial site was an important meeting and cultural point for Africans. Archaeological evidence shows that the dead were laid to rest individually, were buried in coffins, and usually oriented towards the west. The dead were also often positioned with their arms folded or placed by their sides. As time wore on, the burial grounds became denser, so bodies started to be stacked three or four deep in some parts of the cemetery.

After the burial grounds were closed and the grounds were sold, the site was covered and leveled under 7.6 meters (25 feet) of soil. Although its name continued to appear on some old maps of the city, it was eventually forgotten until the end of the 20^th century when it was rediscovered. From 1993 onwards, the African Burial Ground was designated a New York City Historic District and a National Landmark. Then, in 2007, the monument became the first National Monument dedicated to Africans of early New York and Americans of African descent.

History isn’t just something we read about in books. It is something that surrounds us and is sometimes completely out of sight. Construction and renovation projects may represent efforts to do something “new” with a space, but in the process of bringing them into being we can unearth hidden chapters of our pasts, some of which are surprising, some are worrying, and others force us to confront difficult times in the lived environment we inhabit.