10. Carlsbad Caverns
Located in southeast New Mexico, Carlsbad is home to some dazzling limestone formations, from delicate "soda straw" stalactites to an enormous limestone chamber some 4,00 feet long. Self-guided and ranger-led tours direct people through chambers named for their unusual features, like the Kings Palace and the Hall of the White Giant. The caverns also offer a rare opportunity to experience complete darkness, an underground cafe built during the 1950s, and a chamber full of bats that was once mined for guano.
9. Waitomo Glowworm Caves
North Island, New Zealand
Located on the North Island of New Zealand, these caves are famous for...well, for exactly what you'd expect. Thousands of glow worms, unique to New Zealand, glow with bioluminescence that dispels the pitch-black you expect from a cave and makes it seem even more unearthly than your usual cave visit. Of course, even without the glow worms, there are still rock formations, underground pools, and more.
8. Mammoth Cave
Edmonson County, Kentucky
Mammoth Cave is the longest known cave system in the entire world, with over 400 miles of passageway mapped and surveyed and even more unexplored terrain. Plus, Mammoth made our Kentucky state bucket list of activities. There are also many other caves in the region, so if you somehow get tired of Mammoth, you can rappel down Hidden River Cave, or take a boat tour of Lost River Cave.
7. Thrihnukagigur Volcano
Southern Peninsula, Iceland
One of our favorite volcanoes is also one of our favorite caves. The tour, entitled Inside the Volcano, involves a hike up to the crater, a descent into the volcano via an open cable lift, and finally a tour of the interior itself. The tour is very safe—groups are small and several highly-trained guides are with you at all times—so as long as you're up for a bit of a hike, there's no reason not to go for this singular experience.
6. Louisville Mega Cavern
It might not be fair to mention the Mega Cavern here, but something about it keeps us coming back. The Mega Cavern isn't an unspoiled spelunking experience by any means. Instead, it's more like the Disney World of caves. With an underground zip-line course, BMX park, and seasonal Christmas lights display, this is a sight to see—just maybe not for the same reasons as the other caves.
(image via mulligan4130)
5. Marble Caves
General Carrera Lake, Chile
In Chile, the waves of Lake General Carrera have hewn a beautiful cave system out of solid marble. You need a boat in order to travel the caves, but the surreal, swirling beauty of the marble that surrounds you is unlike any other and well worth the trouble it takes to get there. The caves are far from the beaten path, but there are local tour groups who can help you reach it.
4. Škocjan Caves
The Škocjan Caves are a UNESCO World Heritage Site due to the unique ecosystem, the enormous underground canyon, and the fact that they've been inhabited since prehistoric times. An underground river cuts through the canyon—one of the largest underground canyons in the world—and water collects in rimstone pools as well. The steps and footbridge across the chasm, though manmade, are an impressive part of the scenery in their own right. You might just think you're in the Dwarven Mines of Moria.
3. Skaftafell Ice Caves
Vatnajökull National Park, Iceland
This can be tricky—ice caves come and go as glaciers move, melt, and freeze so some of the caves floating around online might not even still exist. On the other hand, they're a popular attraction, and you'll want to book as far in advance as possible. It's worth the hassle, though. Finding yourself surrounded by the eerie blue glow of glacier ice is a pretty unique way to pass a vacation, and the sights are jaw-dropping at Vatnajökull National Park.
Yes; the whole country. Slovakia has over 2,400 caves, meaning that there's something for everyone. The Slovak Karst system, a UNESCO World Heritage site, has some of the world's highest stalagmite formations and an ice filled abyss. Belianska Cave has a naturally-formed auditorium where concerts are held. Demänovská Cave of Liberty's ponds hold cave pearls and cave water lilies, and the list isn't even getting started.
1. Mogao Caves
Mogao Caves are also known as the "Caves of the Thousand Buddhas." Located at a crossroads of the Silk Road, these caves hold some 1,000 years worth of Buddhist art, including statues and documents. The art and artifacts found here show the influences and exchange of ideas that the Silk Road has facilitated for centuries.