This National Park Is Home to the Longest Cave in the World-and Only 426 Miles Have Been Explored So Far
Mammoth Cave in south-central Kentucky hosts the world's longest cave system (over 426 miles), with rich geology, ancient human artifacts, and guided tours.
For over 94% of human existence, our ancestors lived as tribal hunter-gatherers, focusing on obtaining calories to sustain their large bodies and brains, consuming 20% of daily calories.
Computer simulations reveal the first wheel was invented nearly 6,000 years ago
The wheel, a monumental invention, likely originated in the Carpathian Mountains by miners using innovative transport methods, profoundly impacting human progress and labor.