- Pirunkirkko cave has gained a reputation for its contact with the spirit world
- According to a new study, it’s all down to a unique resonance in the cave
Every year, thousands of brave visitors venture to a cave in Finland in the hopes of ‘talking with the Devil’.
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 University of Eastern Finland have revealed why visitors claim to ‘feel the presence of a spirit’ inside the cave.
According to the experts, it’s all down to a unique resonance.
‘Where a researcher of acoustics hears as resonance, people of the past may have sensed the presence of a spirit, and a shamanic practitioner may feel the presence of an exceptional energy, each according to their background,’ said Riitta Rainio and Elina Hytonen-Ng.
Every year, thousands of brave visitors venture to a cave in Finland in the hopes of ‘talking with the Devil’
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
Pirunkirkko is a Z-shaped crevice cave that measures just 111ft (34 metres) long.
In ancient folklore, the cave was known as a place where local sages would meet to the contact the spirit world.
In particular, a man known as Kinolainen regularly used the Devil’s Church for magical rituals.
‘According to folklore, Kinolainen would take his patients to the “church” to talk with the Devil about the causes and cures of their ailments,’ Ms Rainio said.
‘This kind of a healing ritual often included loud yelling, stomping, shooting and banging.’
In their new study, the researchers set out to explore whether the acoustic properties of the cave could help to explain the beliefs associated with it.
Pirunkirkko is a Z-shaped crevice cave that measures just 111ft (34 metres) long
In ancient folklore, the cave was known as a place where local sages would meet to the contact the spirit world
An analysis of the cave revealed that it houses a distinct resonance phenomenon that both amplifies, and lengthens sounds at specific frequencies.
According to the researchers, this phenomenon is caused by a standing wave between the smooth parallel walls of the cave.
This generates a tone at the natural frequency of the cave – 231 Hz – which stays audible for around one second after sounds such as claps, drums, or bangs are made.
As part of the study, the team interviewed and recorded a modern-day practitioner of shamanism who uses the cave for rituals.
‘The practitioner told in the interview that drumming sessions especially at the back of the cave have opened up “new horizons”,’ the team explained.
‘We recorded the shamanic practitioner and found that they repeatedly vocalised tones at 231 Hz, which were then amplified by the cave at its natural frequency.’
While resonance is common in buildings, it’s rare in natural environments – largely due to the lack of solid, parallel surfaces.
For this reason, the researchers suggest that the subtle resonance in the cave may lead visitors to feel like they’re feeling a spirit.
