The biggest cave systems in the USA

Simon Edward • September 4, 2023
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Everything is bigger in the States – from cars to coffees to caves. Join us as we explore 10 of the deepest caverns in the good old US of A.


Everything is bigger in the States – from cars to coffees to caves. Join us as we explore 10 of the deepest caverns in the good old US of A.

Space is often called the final frontier. But here on Earth, there still lay many intriguing underground caverns that, contrary to popular belief, have yet to be explored.


Caves can be huge. Really huge. And exploring their darkest depths is more "confronting the abyss" than "Sunday stroll".


It's a wonder we've explored as much as we have. But brave spelunkers have discovered lots of expansive underground cave networks, some of which stretch for 80 miles or more.


Many of these subterranean labyrinths are located in the good old US of A. So, let's don our cavers' helmets, sing a quick "Star-Spangled Banner" and explore ten of the deepest caves America has to offer.


10. The Hellhole


Why is this cave in West Virginia known as the Hellhole?


One theory suggests the cave was so named because of its intricate and spooky rock carvings. But the most probable reason for its demonic moniker is that it's a nightmare to traverse.

Case in point: type "Hellhole" into YouTube and you'll see cavers passing through what's known as The Corkscrew. This passage is so narrow that a human can't fit through unless they use a very careful twisting technique.


The shape of this cave is so gnarly, in fact, that its distance is difficult to discern. Like a particularly disobedient snake, it winds back and forth in a way that confounds calculation and patience.


So, we've put this cave in the number ten spot even though some estimate it to be as long as 43 miles.


9. Fort Stanton Cave


Tucked away in the humble community of Lincoln, New Mexico, Fort Stanton stretches for a not-so-humble 31 miles.



Picture of Fort Stanton Cave

Fort Stanton Cave is named for a nearby military base and is famous for its velvet formations. These look like soft peat from a mythical forest but are actually made from a special type of crystallised malachite. 


If you find yourself in New Mexico, be sure to swing by Fort Stanton. It's one of the most beautiful places to visit in the American Southwest.


8. Binkley's Cave System


The state of Indiana is flush with intricate caverns. The largest of these systems was recently discovered to be Binkley's, named after the farmer who bought the land on which the cave was discovered.

Dye and smoke bomb techniques had to be used to confirm whether two large caves on the property were connected, as the two systems appear to be fused by only one small shaft a few hundred meters long. The entire system is estimated to run about 37 miles.


7. Friars Hole Cave System


Being big doesn't make a cave accessible. Some of the caverns on our list have only one or two hard-to-find entrances.

Friars Hole Cave System in West Virginia, meanwhile, has a whopping ten. This makes the cave especially fun to visit, as it's easy to locate and delivers a different experience for each of its entryways. (We'd like to try the one called "Rubber Chicken Entrance".)


According to one source, the passageways of Friars Hole stretch for 38 miles. That's the distance from Harrogate to Darlington. Wow!


6. Great Savannah Cave System


Also located in West Virginia, the Great Savannah Cave System runs 44 miles, making it the longest cave system in the state.


Picture of Great Savannah Cave System

With wide open mouths, large paths and surprisingly shallow drops, this system is known to spelunkers as one of the easier cave systems to explore, making it a relatively safe and fun family destination.


Of course, caving always comes with risks, so be sure to follow proper precautions and bring a trusted guide along.


5. Fisher Ridge Cave System


Now we get to the big boys.

Starting out the top half of our list is the Fisher Ridge Cave System in Kentucky. At a whopping 80 miles, it takes a huge leap in size compared to our previous caverns.


Fisher Ridge is nearly split in two, with only a few narrow passages connecting two large systems. It's also one of the most branched cave systems in the US. 


4. Lechuguilla Cave System


New Mexico is responsible for some of the best television in the US. (
Breaking Bad. Succession. We could go on…)

And our next cave has even managed a star turn on UK TV. The Lechuguilla Cave System in Carlsbad, New Mexico, has a "Chandelier Ballroom" that was once featured on BBC's own Planet Earth.


It is quite a stunning space to behold.


3. Wind Cave


Wind Cave in South Dakota is 150 miles long. It's also simply enormous.


Picture of Wind cave

Wind Cave is known as the densest cave system in the world. "Dense" is a bit of a misnomer, though. It's a caving term that refers to how cavernous the spaces are.


In any case, it goes to emphasise just how large the Wind Cave is. Not only does it cover 150 miles of the earth's crust, but it also takes up huge swaths of space as it does. It's a testament to the beauty and grandeur of some of these amazing cave systems.


2. Jewel Cave


Also running under South Dakota, Jewel Cave is the first on our list to stretch over 200 miles.


Picture of Jewel Cave

It's also one of the most gorgeous. Jewel Cave is named for the large calcite formations that make up its inner walls. A breathtaking site, these calcite formations take hundreds or sometimes thousands of years to develop.


Everyone owes it to themselves to view them at least once in their lifetime. But if you can't make it, you should at least visit our next cavernous contender…


1. Mammoth Cave


The name says it all. Spanning over 426 miles is Mammoth Cave in Kentucky.


Picture of Mammoth cave

And the 426 miles is only what we've discovered so far. It's estimated to cover even more ground, but it's so large that spelunkers are still uncovering its massive passageways.


Mammoth Cave is believed to be the largest cave system in the world. It's hardly surprising that it sits at the top of many cavers' bucket lists.


Here at Stump Cross Caverns, we might not have 426 miles of underground caverns – but what we lack in length we make up for in magic, mystery and adventure. Pay a visit to our
UK caves and you'll discover an ancient underground world buried deep beneath the Yorkshire Dales. Up for some safe, family-friendly spelunking? It's easy to book tickets online.


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