World Longest Caves - Mammoth cave

Mammoth Cave - Kentucky, USA

The Mammoth Cave is the longest underground system of labyrinths in the world. The Mammoth Cave is a place of beauty, mystery and paradox. It is now the realm of underground lakes and canyons, waterfalls and streams, narrow passages covered with a dome of large halls. Located 80 km from the city of Bowling Green, Kentucky cave contains one of the world's largest underground tunnels, so that is included in the UNESCO World Heritage List. The mysterious sinkholes, the underground caves, waterfalls and the formation of gypsum karst attract numerous visitors. No one yet knows the true size of the Mammoth Cave. The new cave passages constantly open up the border of this spectacular underground labyrinth extending deeper and deeper into the depths of the underworld. The Mammoth Cave is the longest in the world of the underground labyrinth system, if the second and the third longest cave in the world combined, it still would have remain the longest in the world with a margin of 160 km!

Mammoth cave complex which extends over 352 miles- about the distance from Los Angeles to San Francisco  - and has a maximum depth of 377 feet.