Facts about Caves Part 1: Did you know?

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Beware: You should never explore wild caves alone or without proper gear. Consider getting in touch with a Grotto of the National Speleological Society at www.caves.org or a qualified cave club. These groups are skilled and will train you. Without sufficient knowledge, preparation, and equipment, cave exploring can lead to serious injury or death.

Peering down to a steep plunge in a vertical cave, or the stretching darkness of a long passageway is the best way to sense the mystery that draws so many of us to spelunking. Caves are mysterious even for scientists. There are still tons of facts about caves that are only just being discovered in this century. Caves have many latent secrets that constantly surprise researches. A veil of darkness envelopes the natural beauty that makes us more curious and pushes us to find answers within them.

Here are some interesting facts about caves that prove how little we know about them.

Fact #1: Most Caves Are Created by Water.

No two caves are the same. And this fact is surprising when thinking about how many caves exist far below the surface of the Earth. But most caves in the world really are hollowed out of the rock by water; they’re born after a lengthy erosion process. Water seeps through the ground and creates holes inside them. That’s why we typically find them in rocky areas. Some caves are natural too. They have no association with the erosion of water. They are just holes beneath the surface of the earth.

Narrow passages inside the earth can become caves too. It is possible, but this process requires thousands of years, and it happens mostly in solutional caves. These caves are often created in soluble limestone, but have been found in many other types of rocks like marble, chalk, and dolomite as well.

Lava caves are the rarest caves; after all, they only form near volcanoes. It is very hard to visit these, and they are dangerous as magma often still flows beneath them. Ice caves, on the other hand, are also rare visited but are a bit safer. They have the ceaseless energy of the ocean waves that compels the cavers to spend time inside them and even use them for yoga or meditation locations.

A look inside a lava cave, with a long grey passageway that looks like a tube.
Lava caves can be very slippery and dark.

Fact #2: Most of the world’s caves are still unexplored.

Believe it or not, we don’t know how many caves there actually are. People think humans have discovered and explored every caving system on the earth; this isn’t correct. We have scratched the surface surely, but scientists believe much bigger hidden caves exist than the caves we know. We hope as caving gets more popular, lots of new and interesting discoveries are made.

However, some experts believe we have only discovered about 1%. Can you believe that? Cavers still have about 99% unexplored territory. So while there’s several famous caves like the 4 we’ve shared here, there’s actually millions of caves we have yet to find.

Fact #3: You might be sitting on top of a cave right now.

Many caves in the world have no entrance at all. Closed off entirely, we don’t even know most of them exist yet. It is very difficult to spot them from above the ground when they could be 50 meters below the surface. As you read this, you are probably sitting on top of some unique and large cave systems yourself!

Fact #4: Stalagmites and Stalactites are not the same thing.

A cave features hundreds of stalactites hanging over a body of water.
Here’s an easy way to remember: stalactites (with a letter C) are like icicles, and hang down from above. Stalagmites (with a G) come from the ground, and point upward from below.

Some facts about caves, like this one, appeal to your inner scientist. People confuse ‘Stalagmite’ and ‘Stalactite’ all the time. The main difference between both of them is the stalagmite grows from the surface of the earth, while the stalactite hangs from the ceiling of the cave.

Both form when water drips from the ceiling. When dissolved calcium bicarbonate comes in contact with the air, gravity gives it a special form. Stalactites in particular are dangerous; they grow as fast as a centimeter per year and can randomly fall from the ceiling. Some can get quite large, so you have to be extremely careful while walking.

In a stalactite or stalagmite cave, try not to touch anything. The buildup is formed by minerals. Your skin contact against even a stalagmite on the ground, can alter the surface tension and make the chemical water flow.

Fact #5: People DO still find hidden treasures while caving.

One of the most exciting facts about caves is that there is always a chance to discover something unbelievable. If you have heard of how ancient treasures and artifacts have been found inside caves in the past, you might think it’s all been found. But you haven’t missed out yet.

Our ancestors often used caves for burials and shelters throughout history, and we have not yet found everything that has been left behind. There are still thousands of caves that have yet to be found, and many known caves that have never been fully surveyed.

In some regions, people utilized caves as their religious sites also. Therefore, it is not uncommon to find bones or treasure inside them. Check out this discovery in Israel just a few years ago!

Fact #6: There are 3 main categories of caves.

All types of caves can be divided into three main categories – open-entrance caves, closed-entrance caves, and entranceless caves. Open-entrance caves are visible and have a good, wide opening. Every show cave or tourist cave is an open-entrance cave as their entry point is obvious.

The closed-entrance cave is the cave which is closed off by the falling of rocks or flood. Caves that are collapsed also fall into this category. Some wild caves can be considered as closed-entrance if the entry passage is too tight or the rocks make it almost impossible to enter inside them.

The last category is the entranceless category. It is a completely closed system and can only be opened by professional scientists. They create an entrance by using drills and explosives. For a normal caver, it is not possible to explore the entranceless system.

Fact #7: Mammoth Cave is full of wonders.

We can’t share interesting facts about caves without mentioning Mammoth Cave. Aptly named, Mammoth cave is one of the longest cave systems on the planet, packed with secrets over a million years old. It has 40 different ancient species of shark fossils that are preserved in the limestone.

Researchers are absolutely amazed at the diversity of ancient sharks that they found in the passages of this single cave system. At least 6-8 fossils were new to science, and they think more unique fossils still lay waiting for discovery.

A large group gathers for a tour of Mammoth Cave, in Kentucky.
A large group gathers for a tour of Mammoth Cave, in Kentucky.

Fact #8: Your eyes will not adjust well inside a cave.

If you think your eyes can get used to the dark inside the cave, you are not correct. It’s not like sitting in your room with the lights off – the inside of a cave is very different.

When light cannot penetrate far inside a remote location like a cave, the darkness is almost overwhelming. Even if you spend hours inside a cave without a headlamp, you won’t be able to see anything.

This is why responsible cavers are very meticulous about their flashlights and headlamps; they know that there is nothing for their eyes to adapt to. Be sure you are prepared with a good headlamp and at least one or two backup light sources.

Fact #9: Scientists have explored caves down to 7200 feet!

The maximum depth of the cave system is around 9,800 ft. At this depth, the pressure of the overlying rocks plays an important role and often collapses the cave. But the deepest limit which scientists have explored is approximately 7,200 ft. Professionals measured this depth in the Krubera Cave in Georgia.

A great view of Voronya Cave in Georgia, known for its incredible plunge.

Fact #10: Some animals live only inside caves.

Here’s a word you’ve probably never heard before: Troglobite. That’s what you call an animal that only lives inside a cave.

These animals often have unique characteristics which you will not find in other animals. For example, due to the extremely limited or no light inside the cave, they have reduced or no vision. Some animals, like blind cave fishes, don’t even have eyes. They never leave the caves and so you will sometimes only find them in one location on Earth.

Animals like bats aren’t Troglobites though; caves are for their sleep and reproduction only. They leave the cave often to hunt food, and can be seen flying out of some caves in large groups depending on the season. However, you can expect to come across some bats while you’re inside.

Learn more about cave animals here.

A close up view of a pair of blind cave fish from Mexico.


We hope you enjoyed these 10 interesting facts about caves! As many other cave enthusiasts, we’re always looking to learn more fascinating things about these relatively unexplored and undocumented areas below the surface. What cave or cave diving facts have you heard of? Share them below!

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