The national park of Koli in eastern Finland is home to a famous, 34-meter-long crevice cave known as Pirunkirkko, or Devil's Church in English. In folklore, this crevice cave was known as a place ...

The Pirunkirkko cave – or Devil's Church in English – sits in the national park of Koli and has gained a reputation for its alleged contact with the spirit world. Now, researchers from the ...