Dense fog fills Kentucky cave in rare spectacle, photos show. ‘Portal to another world’

A massive cave system in Kentucky seemed to create a weather system of its own, photos show, a thick bank of underground clouds that delighted recent visitors.

In a rare spectacle that only happens under “perfect conditions,” fog formed inside Mammoth Cave National Park, park officials said in a Facebook post Monday.

“Today we had a large and unexpected storm come through the park which caused a quick drop in the temperature,” the post said. “This pressure change caused the airflow to reverse, pulling into the cave, resulting in a dense fog filling the Rotunda room!”

The world’s longest cave system, with limestone corridors branching out for potentially 1000 total miles, apparently has more ways to impress than sheer size.

“That is not fog. That is clearly a portal to another world,” one person commented.

It’s either fog, “or Snoop Dawg visited,” said another.

This isn’t the first time fog has filled the cave, but it’s far from a common occurrence.

“This happens infrequently,” park officials said. “Only with the perfect conditions between the surface and the cave.”

It’s even more rare to witness, as the fog comes and goes quickly.

“After about 10 minutes the fog dispersed,” park officials said. “It was a very neat thing to experience.”

This story was originally published June 14, 2021 at 10:07 AM with the headline "Dense fog fills Kentucky cave in rare spectacle, photos show. ‘Portal to another world’."