For some of the caves listed below, you’ll need some pretty gnarly climbing / spelunking equipment and a support crew.

For others, all you’ll need is a pair of sneakers and a few dollars.

In any case, after checking out these pics you may want to read up on how to become a good caver.

1

Crystal Cave - Mexico

Giant Crystal Cave, in Naica, Chihuahua, Mexico, contains some of the largest crystals ever discovered. The crystals - the largest one being 39' long and weighing 55 tons - were formed over 500,000 years when a magma chamber under the cave heated and filled the ground water with minerals. Researchers believe there might be other caverns with giant crystals, but to get to them, they would have to demolish the crystals that have already been discovered. Photo: "Arjuna" Zbigniew Bychowski

2

Stephen's Gap - Alabama

This vertical cave in Alabama can be entered either by repelling the 143' drop through a keyhole, or scrambling down some rocks through a second entrance. Either way you might get splashed by the waterfall that enters the cavern near the ceiling. Photo: Jeffrey Rease

3

Blue Grotto - Capri

The entrance to the Blue Cave is so close to sea level that visitors usually drive up in a motor boat, then change to a small row boat and lie flat on their backs as they pass under the rock entry way and into the cave. Inside, a second underwater entrance - which is 10 times bigger than the surface level entrance - provides light that makes the cavern appear bright blue. Photo: Biker Jun

Intermission
36

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by Hal Amen
9

10 caves to explore in Bermuda

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18

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4

Callao Cave - Philippines

Calloa Cave, in the Cagayan Valley, consists of seven chambers, each with natural crevices that provide light. The largest chamber, known as the Cathedral, is used by the local people as a chapel and can be visited by tourists. Photo: Melchor Labagala

5

Majlis al Jinn - Oman

This is the ninth largest cave chamber in the world; locals know it as Khoshilat Maqandeli. It was discovered by Americans W. Don Davison, Jr. and his wife, Cheryl S. Jones in 1983. Cheryl's Drop is one entrance where you can repel 158.2' into the chamber. Photo: Chris Haigh

6

Sea Lion Cave - Oregon

Sea Lion Cave, on the Oregon coast, is a privately owned cave that contains the wintering grounds for over 200 Stellar Sea Lions. There are also spots to view whales and bald eagles. Photo: Craig Elliott

7

Crystal Cave - Bermuda

According to local legend, Crystal Cave was discovered by two boys searching for a cricket ball in the grass. Another boy, the property owner's son, was lowered into the cave to check it out. Today the 500 meter long underground cave is Bermuda's most famous, and contains waterways as well as caverns with stalactites and stalagmites. Read this post for nine other caves to explore in Bermuda. Photo: Tim Conway

8

Tadrart Acacus desert cave - Algeria

In the Tadrat Acacus desert, between the Tadart Acuscus Mountains near the Algerian border, are caves containing UNESCO World Heritage rock-art dating 12,000 BC to 100 AD. The rock-art in this region is in danger due to petroleum drilling. Photo: Alessandro Vannucci

9

Cueva de los Verdes - Canary Islands

Greens’ Cave, in English, is technically a lava tube. It is almost 5 miles long, and has a concert hall set up near its entrance. Parts of the cave are lit up for visitors. Photo: Timo Frey

Intermission
20

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by Hal Amen
2

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by Joe Batruny

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by Matt Hershberger
10

Cenote Ik Kil - Mexico

A cenote is a cave with no roof, or a sinkhole. Cenote Ik Kil is about 200' in diameter and 130' deep with vines extend from the ceiling to the water. It's a popular swimming destination for tourists. For more on cenotes, check out Juli Huang's report from cenotes in the Mexican Riviera. Photo: Elvis Pépin

11

Carlsbad Caverns - New Mexico

Carlsbad Caverns are visited by 407,000 people every year. It's made up of 117 caves; three are developed caves (one has an elevator) for public tours. There are also undeveloped caves designated for “adventure caving tours." Photo: Shadow Hunter

12

Badami Caves - India

The Badami Cave Temples located in Karnataka, India is an example of Indian rock-cut architecture from the 6th and 7th centuries. Four distinct caves were carved into limestone walls. The first three caves are of Vedic faith dedicated to Vishnu and Shiva and the fourth is a Jain Temple. Photo: Anoop Negi

13

Mammoth Cave National Park - Kentucky

Mammoth Cave National Park in Kentucky was established in 1941. It is the home of the longest cave system known in the world with 390 miles of passageways. The cave is named for its size, not the extinct animal. Photo: Alex Zhu Photography

14

Batu Caves - Malaysia

The Batu Caves are both an important Hindu shrine and a popular Malaysian climbing site. During the Hindu festival, Thaipusam, a procession ends at Batu Caves where offerings are left for Lord Murugan for whom the shrine is dedicated. The main caves can be reached by 272 steps up the hill. For climbers, the caves offer over 160 routes and reach 150 meteres. Just be wary of the monkeys! Photo: Steve Cornish

15

Blue Caves Zakynthos - Greece

On the Greek Island of Zakynthos, the Blue Caves are cut into the cliffs around Cape Skinari and can be reached only by small boat. The white walls and pebbles of the floor reflect light giving the caves their blue hue. Photo: objektklasse

Intermission
6

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by Hal Amen
2

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by Matt Hershberger

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by Joe Batruny
16

Jenolan Caves - Australia

Jenolan Caves in Australia’s Blue Mountains (~50 km west of Sydney) are the oldest discovered open system in the world, according to Australian geologists. It was also the first cave to install electric lighting in 1880. There are 40 kilometers of known passages. Though there is no public transportation to the caves, they are a big tourist attraction, bringing in 250,000 visitors every year, and the area around them is developed with hotels and restaurants. There are 10 caves that are developed for self-guided and regular daily walking tours, but much of the system is undeveloped and only explored by cavers. Photo: Peter Kennett

17

Reed Flute Cave - China

The Reed Flute Caves are over 180 million years old and has preserved ink inscriptions inside that date back to 792 BC. The cave was rediscovered by Chinese refugees fleeing Japanese troops in the 1940s and named for the reeds growing outside its entrance. Photo: Bernt Rostad

18

Surprise Cave - Vietnam

On Bo Hòn Island, Surprise Cave is part of the UNESCO World Heritage site Halong Bay. The cave was discovered in 1901 and was used by the Viet Cong as a hideout during the Vietnam War. The cave is big, but so are the crowds and tour groups that come here by boats from the Bay. Want to see Vietnam's largest cave? Check out this photo gallery. Photo: Frampton Panchong

19

Fingal's Cave - Scotland

On the uninhabited Scottish island of Staffa, Fingal’s cave, is famous for its mysterious echoes and its hexagonally shaped basalt stone columns. It can be reached by boat; tours run from April to September. Photo: Graham McKenzie-Smith

20

Jewel Cave - South Dakota

At 157 miles long, Jewel Cave - named a National Monument in 1908 - is the second longest cave system in the world. It was discovered in 1900 and named for the crystals seen from the entrance. Today it is maintained by the Park Service who offer a scenic tour, a historic tour, and a spelunking tour year round. Photo: Abir Anwar

21

Bear Cave - Romania

Discovered in 1975 in the Apuseni Mountains, legend has it that the cave was once a home to many bears, and when a rock covered the entrance to the cave, 140 bears were trapped and killed inside. Visitors can enter a few different parts of the cave, including the Bears Gallery where all 140 skulls are preserved. Photo: Cristi Man

22

Qumran caves - Israel

The Qumran Cave system in the West Bank is the archeological site where the Dead Sea Scrolls were first discovered in 1947. The area is made up of real limestone caves, and artificial ones built into the cliffs. Visitors today can walk along the site and up to the caves on walking paths, some of which have views of the Dead Sea. Photo: James Emery