Spelunking, aka caving, is an increasingly popular recreational activity. People involved in it find pleasure in exploring the special worlds that feature different types of rock formations, underground lakes, and other interesting things. Unlike speleology, which is the scientific study of caves and the cave environment, spelunking enthusiasts explore caves mostly out of curiosity and strive for adventures, rather than scientific interest.

The good thing about spelunking is the immense number of caves found all over the world. Only in the United States, there are approximately 45, 000 caves! The amount of caverns in the entire world is yet to be known, because many of them are being discovered accidentally. So we can only try to imagine how many more interesting caves there are to explore.

So let's take a look at the most magnificent caves found out there in the world, from the United States to China, and from New Zealand to Iceland. Some of these caves require tons of spelunking experience and knowledge of how to operate in the underground world, while others don't require anything but a pair of good shoes, a headlamp and some enthusiasm. To access some of the caverns, it's necessary to climb or descend by the rope, while others have much easier on-foot entrances. Some of them are illuminated by colored lights, while others are kept dark and authentic.

But there's something that is similar for all caves we know. All of them offer spelunking enthusiasts to explore unusual and surreal cave-scapes, showing how powerful and creative our Mother Nature is.

19 Alabama: Stephens Gap

Stephens Gap is suitable for intermediate level spelunking enthusiasts, who like caves as well as waterfalls. Spelunkers can access the cave using one of the two entrances - they may either descend using a rope, or simply walk down. The second way can be hazardous, because the cave's walls are slippery, so explorers should be extremely careful.

The cave is spectacular! It has a tall vertical pit and a natural pedestal, where tourists like to take photos.

Spelunkers are strongly recommended to wear helmets, sturdy shoes, and headlamps while in the cave. It's also better to have minimal vertical caving skills to stay safe and get the ultimate experience of the cave.

18 Oman: Majlis Al Jinn

Majlis al Jinn translates from Arabic as a meeting or gathering place of the Jinn. This translation sounds so wonderful that it makes me feel like going to Oman to explore this cave!

This natural wonder is currently known as one of the largest underground caves in the world. Its area is striking 58 thousand square meters. Its width is 225 meters and its length is 310 meters. Even though the cave is huge, it's rather hard to spot it, because it opens to the outside with only three small entrances. It was discovered by accident and the first person explored the cave in 1983.

Spelunkers can descend into the cave by ropes to see its splendid geological formations.

17 Canary Islands, Spain: Cueva de Los Verdes

Cueva de los Verdes is one of the main attraction sights in the Canary Islands. About 3000 years ago, it was formed due to lava flows erupting from Monte Corono, a volcano standing nearby. As it usually happens with lava tubes, lava stream's upper parts cooled down after some time and formed a solid crust.

There's one entrance into the cave. Tourists can explore this natural wonder since 1960, when two kilometers of the cave were developed and its walls were illuminated. It's interesting that the cave also has a concert hall that seats up to 500 people. The cave surely has great acoustics, so listening to concerts there should be a magnificent experience.

16 New Mexico: Carlsbad Caverns

Carlsbad Caverns is one of the most popular attraction sites for tourists in New Mexico. The first man entered the caves back in 1898. Today, a lot of spelunking enthusiasts traveling across the United States visit it to get a one-of-a-kind experience. Of course, the caves are well-developed these days and feature trails and lights for tourists to gaze at splendid rock formations, fossils, and cave pools.

Spelunkers are offered a number of tours into the caverns. They can choose a self-guided, ranger-led, or beginners tour, depending on their training level. All tourists should wear proper shoes and bring AA batteries, headlamps, and water to safely explore the cave.

15 Australia: Jenolan Caves

The Jenolan Caves were carved by rivers millions of years ago. Now, they're one of the most magnificent tourist attractions in Australia and one of the oldest caves in the world. A lot of tours are provided to help multiple tourists, from children to adults, from amateurs to professional spelunkers, to explore the caves daily.

Throughout the years, geological processes created stunning natural masterpieces inside the caves. There are multiple stalactites and stalagmites, as well as massive columns and sparkling crystals. Their view can amaze any tourist, whatever spelunking experience they have. So everyone who enters the Jenolan Caves should be prepared to have their jaw permanently dropped!

14 Mexico: Crystal Cave

This magnificent cave is located in Naica, Chihuahua, Mexico at a depth of 300 meters. The cave features one of the largest natural crystals on Earth. The biggest crystal found in the cave to date weights 55 tons. It's 12-meter long and its diameter is 4 meters.

The Crystal Cave was discovered only in 2000 by miners working in the area. Since then, it's been actively explored by scientists and tourists. However, due to its conditions, it's prohibited to make any unsupervised visits. The temperature inside the cave reaches 58 degrees Celsius and humidity is as high as 99%. To cope with these harsh conditions for longer than 10 minutes (and survive), visitors have to wear ice-packed vests under their caving suits.

13 South Dakota: Wind Cave National Park

The Wind Cave in South Dakota is the fourth largest cave in the world. It received its name from the strong and cold winds that blow from the cave's entrance and then change directions and blow in and out.

Inside the cave, spelunking enthusiasts can see thin and exquisite calcite formations called popcorn, honeycomb, boxwork, and frostwork. The cave is full of unexplored areas. It's believed that only 10% of its passages have been discovered so far. So those spelunkers who would like to be the first in their caving experiences and find new passages in the maze of the Wind Cave should certainly visit it.

12 Capri, Italy: Blue Grotto

The Blue Grotto is a cave located on the island of Capri. The sunlight penetrating into this sea cave shines through the sea water and creates a blue reflection on the cave's walls. It creates magnificent illumination inside the grotto.

The cave extends into the cliff for 60 meters. It's 25-meters wide and 150-meters deep. The entrance into the cave is only one meter high, and, for this reason, it's possible to enter it only when there's no storm in the area. And even when the waters are calm, visitors need to lie down in their small boats while entering the cave.

The Blue Grotto is certainly worth visiting, because it's a rare opportunity to see a cave flooded with brilliant blue light.

11 Vietnam: Surprise Cave

There are a lot of caves in Halong Bay, Vietnam, and the so-called Surprise Cave is one of the most popular ones. Currently, this cave, as well as Halong Bay itself, is considered UNESCO World Heritage site.

Surprise Cave was discovered in 1901. It's believed that the Viet Cong used it as a hideout location in the times of the Vietnam War. It's undoubted that they could find a lot of places to hide there, because the cave is huge.

Surprise Cave is certainly worth visiting due to its magnificent rock formations and sparkling illumination. When you get in there, you feel like you're in a fairy tale!

10 Bermuda: Crystal Cave

There are a lot of things that attract tourists in Bermuda, and its caves are one of the main reasons to visit the islands. It's believed that the first caves of the island began forming over one million years ago, when the sea level was much lower than it is today.

Crystal Caves are one of the largest and most awe-inspiring cave systems in Bermuda that are certainly worth visiting for all spelunking enthusiasts. They feature stunning stalactites and stalagmites, as well as limestone icicles dripping from the ceiling, intricate rock formations, and a pristine underground lake (17 meters in depth).

A lot of tours are provided in the area to help tourists explore the cave and get an unforgettable experience gazing into the super-clean waters of its lake.

9 Arkansas: Cosmic Cavern

Cosmic Cavern was discovered in 1845, but developments in it began only in 1927. Now the cave is open for tourists, who would like to get an ultimate caving experience and see magnificent rock formations.

The cave is nicely warm and humid all year round, which makes it comfortable to explore it in any season. It features two lakes. The water in them is pristine and their bottoms haven't been found yet. For this reason, the lakes are still considered bottomless.

Since Cosmic Cavern is one of the most beautiful and awe-inspiring caves in the United States, it's certainly worth visiting for tourists traveling across the country.

8 Malaysia: Batu Caves

Spelunkers traveling to Malaysia should certainly visit Batu Caves that include a series of limestone caves and cave temples. This site is a popular Hindu shrine that is consecrated to Lord Murugan, a Hindu god of war and son of Shiva and Parvati. Hindus worldwide hold the caves sacred and gather there to celebrate a yearly full moon festival.

The rock formations featured in the Batu Caves have been formed for thousands of years, and now there are multiple cave curtains, flow stones, cave pearls and scallops that create the magnificent views inside the caves.

The caves also have a rich fauna that includes a number of spiders, snakes, bats, and monkeys.

7 Iceland: Thrihnukagigur Volcanic Cave

Thrihnukagigur is a dormant volcano located in Iceland. It hasn't erupted since the 2nd century BC, and these days it's considered a natural phenomenon that amazes everyone who dares to descend into the magma chamber and gaze at its walls. Normally, the chamber would be filled with magma, making the exploration impossible. However, the magma in Thrihnukagigur drained away for some reason and made it possible to gaze inside a dormant volcano.

The cave was discovered in 1974 and it was opened for tourists and spelunkers only in 2012. Since it's the only volcano in the world visitors can safely explore with the help of an elevator, it's certainly worth visiting.

6 Kentucky: Mammoth Cave National Park

Mammoth Cave is one of the largest known cave systems in the world, a UNESCO World Heritage site, and an international Biosphere Reserve. It features a number of vast chambers and complex limestone labyrinths, 643 kilometers of which have already been explored.

Unlike many other caves, Mammoth Cave doesn't have any illumination inside. Instead of glamorizing the interior with colorful lights, it shows the authentic underground scenery to its visitors. The tourists and spelunkers who would like to experience total darkness can visit the cave at any season, because it constantly has a nice warm temperature that is perfect for pleasurable exploration of it numerous labyrinths.

5 Scotland: Fingal's Cave

Scotland has a lot to offer to tourists, and Fingal's Cave is one of the sites that are certainly worth visiting. This sea cave is part of a National Nature Reserve that is popular for its natural acoustics.

Fingal's Cave consists of jointed basalt columns. Contracted and fractured four-sided blocks were formed by the solidified lava flow that continued cooling down and resulted in the formation of six-sided pillars. The views created by the nature are certainly the most magnificent!

This cave has been inspiring millions of people over hundreds of years. It was an important legendary site for the Celts, Jules Verne mentioned it in his several novels, and even Pink Floyd used the cave's name in one of their songs.

4 China: Reed Flute Cave

Reed Flute Cave is one of the most important tourist attractions for spelunkers visiting China. This natural limestone cave is more than 180 million years old. It has three entrances through which visitors can enter it by foot. Its length is 240 meters. The cave features amazing rock formations, as well as inscriptions that were made in the end of the 8th century AD, when the Tang Dynasty ruled China.

The colored lighting that illuminates the cave creates a surreal underground cave-scape that features massive stalactites and stalagmites. The view inside the cave will amaze even experienced spelunkers.

The name of this cave derives from the reed growing outside of it that can be used to make flutes.

3 Minneapolis: Minnehaha Falls Cave

Minnehaha Falls Ice Cave is a must-see site for all spelunkers traveling across the United States. Even the least experienced spelunking enthusiasts can access this cave and gaze at the frozen waterfall from the inside.

The best time to visit the site is early and late winter, because in this period the waterfall is frozen, but there's still some water flowing over it. This way, the view and the sound create a perfect ambiance for anyone who decides to step into the cave.

Of course, when you're inside the cave, it's highly recommended to take photos, because it's unlikely that you'll see such a scenery anywhere else in the world!

2 South Africa: Cango Caves

The Cango Caves are extremely popular among tourists who like caving. They feature a long system of explored chambers and tunnels that go for over 4 kilometers. However, a large part of the caves is still unexplored. There's a legend saying that the cave’s first official guide walked along the cavern for 29 hours in 1898 and allegedly reached 25 kilometers from the entrance. We're yet to see if it's only a legend, or the cave is actually that long.

To enter the caves, tourists need to join a supervised group. The tour along the caves can take from one to one and a half hours, and at times it requires tourists to climb through the passages as narrow as only 15 centimeters.

1 Virginia: Luray Caverns

Luray Caverns were discovered in 1878 and they have attracted multiple visitors since then. The interior of the caves features stalactites, stalagmites, columns, mud flows, mirrored pools, and flowstone.

The most unique thing about Luray Caverns is the Great Stalacpipe Organ that was placed inside the cave in 1956. It's an electrically activated lithophone that is operated with the help of a custom console. The organ consists of the rock formations that can produce the sounds similar to those of bells, tuning forks, and xylophones. Some artists recorded music inside the Luray Caverns with the help of this organ. It must have been a one-of-a-kind experience!

References: The Outbound, Wikipedia, Oman Tourism, USA Today, Australian Traveller, All That Is Interesting, Hertz, Matador Network, Go to Bermuda, Bermuda Attractions, National Park Service, National Geographic, Atlas Obscura, Big Boy Travel, Stuff