United States
Mammoth Cave
Welcome to Kentucky! Mammoth Cave is a colossal maze of underground passageways, the longest cave system ever discovered anywhere on Earth.
Why is it famous?
It's the longest known cave system in the world, by a huge margin.
Explorers have mapped over 400 miles of passageways, and new tunnels are still being found.
How was it formed?
Underground rivers slowly dissolved layers of limestone rock over millions of years.
As water carved deeper, it left behind a maze of connected tunnels, rooms, and passageways.
Amazing facts
Explorers have mapped more than 426 miles of passages inside the cave.
The next-longest cave system in the world isn't even half as long.
Quick facts
- Explorers have mapped more than 426 miles of passages inside the cave.
- The next-longest cave system in the world isn't even half as long.
- The cave is home to eyeless fish and other creatures adapted to total darkness.
- People have explored parts of Mammoth Cave for over 5,000 years.