Was ‘witchcraft’ in the Devil’s Church in Koli based on acoustic resonance?
The entrance to the cave is only 1 m × 1.3 m in area, bordered by upward and downward bulging boulders. A roundish stone acts as a threshold above which one must bend to crawl. The first outer corridor is 6.4 m long, 1 m wide, and 1–2 m high. It ends in a rectangular corner that is the darkest place in the whole cave . Credit: Open Archaeology (2023). DOI: 10.1515/opar-2022-0328
The national park of Koli in eastern Finland is…