Over 390 miles.
More then 390 miles of passageways have been mapped.
Over 400 miles of passageways have been mapped and surveyed in Mammoth Cave National Park, making it the world's longest known cave system. Extensive exploration and mapping efforts have been ongoing to document the complex network of underground passages and chambers.
over 1,000 miles
over 1,000 miles
over 1,000 miles
Over 390 miles
It contains over 390 miles of mapped passageways.
* Stalactites grow from the top down. * Stalagmites grow from the bottom up. * When they join you have a column. The other forms of speleothems include: * Flowstone * Dripstone * Anthodites * Helicites * Chandeliers * Straws and * Draperies Cave popcorn, snotties and cave pearls also exist and 10 mm cave pearls and larger are special finds for speleologists,
Over 390 miles of passageways have been mapped.
More than two hundred miles. Well over 300, with Flint Ridge Cave to which it connects - the combined system is the world's longest known.
It is the Mammoth-Flint Ridge Cave system with over 390 miles of surveyed and mapped pasageways.
over 1,000 miles