Volunteers help identify hundreds of undiscovered prehistoric burial mounds

More than 6,500 volunteers contributed to the precise identification of around 1,000 prehistoric burial mounds in the Netherlands in just four months, proving the value of involving volunteers in archaeology.

In 2018, the Heritage Quest project was launched to harness the power of citizen scientists, using crowdsourcing to identify archaeological features on lidar imagery of the central Netherlands.

With the participation of thousands of people online, prehistoric burial mounds were identified across the region in a short time. However, the accuracy of crowdsourced data has been questioned in the past because the majority of volunteers are not professional archaeologists.

“Even though the volume of data exceeded our expectations, we faced a major challenge common to large citizen science projects: how reliable are the detections made by volunteers? says lead author of the research, Dr Quentin Bourgeois from Leiden University.

To assess the accuracy of the data, the authors conducted a ground survey of 380 sites identified during the study, examining them in person to determine whether they were in fact prehistoric burial mounds. Their results are published in the journal Antiquity.

According to Dr. Bourgeois, the results are clear. “Citizen science works. We found a direct correlation between the number of volunteers identifying a potential archaeological object and its likelihood that it is a prehistoric burial mound.”

This means the Heritage Quest project has discovered 1,000 previously unknown burial mounds, doubling the number of known mounds in the region in just four months.

Importantly, it shows the value of involving volunteers in archaeological projects, enabling the identification of archaeological features much more quickly than professionals could do alone.

“What would have taken professional archaeologists years was achieved in a few months thanks to the combination of lidar technology and citizen participation,” adds Dr. Bourgeois.

This also has implications for heritage policymaking, as local governments can apply citizen science to quickly and cost-effectively identify heritage sites for protection. In the future, the authors plan to combine volunteer participation and machine learning, thereby identifying archaeological sites on an even larger scale.

However, according to Dr Bourgeois, the most interesting part of the research was seeing how volunteer participation led to greater community engagement with archaeology, thereby producing strong advocates for the region’s heritage.

“I am amazed by the number of previously unknown burial mounds that volunteers have helped to discover,” concludes Dr. Bourgeois. “I knew we were working in an important area with many traces of a prehistoric landscape still preserved, but I didn’t expect to find so many so quickly.

“But for me, the most astonishing result is seeing the passion of the volunteers for our research. They have now become ardent defenders of the preserved traces of prehistoric landscapes in their region.”