Mammoth Cave National Park

Mammoth Cave National Park preserves the world's longest known cave system — a sprawling underground labyrinth of more than 426 miles of mapped passageways, with more being discovered every year. Located in south-central Kentucky, the park sits in the rolling hills of the Green River valley, where layers of limestone have been carved by water over millions of years into one of Earth's most extraordinary natural wonders.

Human history in Mammoth Cave stretches back more than 6,000 years. Native Americans mined gypsum and other minerals from the cave's passages long before European settlers arrived. In the early 1800s, the cave became a tourist attraction — one of the first in the United States — drawing visitors eager to experience its massive rooms, underground rivers, and strange formations. During the War of 1812, saltpeter mined from the cave was used to make gunpowder.

Today, Mammoth Cave National Park offers far more than underground exploration. Above ground, the Green and Nolin Rivers wind through forested valleys, over 70 miles of hiking trails crisscross the ridges, and campgrounds provide a base for multi-day adventures. Whether you're a first-time visitor or a seasoned caver, Mammoth Cave has something you won't find anywhere else on Earth.