‘Devil’s’ cave was thought to contain spirits — but ‘rare’ phenomenon was at play

‘Devil’s’ cave was thought to contain spirits — but ‘rare’ phenomenon was at play

The phenomenon is seldom seen in the natural world, Finnish researchers said.

‘Devil’s’ cave was thought to contain spirits — but ‘rare’ phenomenon was at play

The phenomenon is seldom seen in the natural world, Finnish researchers said.

‘Devil’s’ cave was thought to contain spirits — but ‘rare’ phenomenon was at play

The phenomenon is seldom seen in the natural world, Finnish researchers said.

‘Devil’s’ cave was thought to contain spirits — but ‘rare’ phenomenon was at play

The phenomenon is seldom seen in the natural world, Finnish researchers said.

‘Devil’s’ cave was thought to contain spirits — but ‘rare’ phenomenon was at play

The phenomenon is seldom seen in the natural world, Finnish researchers said.

‘Devil’s’ cave was thought to contain spirits — but ‘rare’ phenomenon was at play

The phenomenon is seldom seen in the natural world, Finnish researchers said.