Adventure travelers are often willing to go to the ends of the Earth just to have an opportunity to witness first hand some of the truly spectacular landscapes that spread out across our planet. From snowcapped mountain peaks to endless miles of ocean coastlines, there are certainly plenty of breathtakingly beautiful places that have the managed to capture our imaginations. But some of the most beautiful places aren't necessarily found on the surface of the planet at all. In fact, there is plenty to be seen beneath it as well. Some of the most amazing sights that nature has to offer can actually be found inside the Earth's countless caverns and caves, with potentially thousands of miles of subterranean tunnels to be explored. With that in mind, here are six great cave systems that every adventure traveler should have on his or her list of places to visits.
Carlsbad Caverns National Park (United States)
Southern New Mexico is home to one of the best cave systems in the entire world in the form of Carlsbad Caverns National Park. Over the centuries, sulfuric acids have dissolved the limestone there, creating one of the most magnificent underground landscapes found anywhere on the planet. With more than 119 known chambers and over a hundred miles of passageways, Carlsbad Caverns is a true wonder to behold. Top of the list is the "Big Room," a massive chamber that is more than 4000 feet (1220 meters) in length, 625 feet (191 meters) in width, and 255 feet (78 meters) tall. Visitors can choose to hike down into the caves themselves or take an elevator from the visitor center that drops an impressive 754 feet (230 meters) over the course of just a few minutes.
Son Doong Cave (Vietnam)
Measuring over 5.5 miles (8.8 km) in length, the Son Doong Cave in Vietnam holds the distinction of being amongst the largest single caverns in the entire world. First discovered in 1991, and later mapped by an expedition in 2009, the cavern actually opened for tours for the first time in 2013. The cave is so massive that its ceiling towers more than 400 feet (122 meters) overhead, and much of the chamber is continually shrouded in darkness even when visitors come armed with bright lights. Visiting Son Doong isn't easy either; It is located deep in the heart of Vietnam's dense jungles, and only one operator is currently licensed to lead tours into the interior of the cave. Oxalis Adventures offers a 7-day/6-night expedition that should appeal to even the most seasoned adventurer looking for a unique experience unlike any other.
Mulu Caves (Borneo)
Borneo's Gunung Mulu National Park is home to a series of underground caverns that are amongst the largest in the entire world, at least in terms of total surface area. They include the massive Sarawak Chamber, which is 2300 feet (700 meters) in length, 1299 feet (396 meters) wide, and 230 feet (70 meters) tall. It feeds into nearby Deer Cave, which is one of the largest cave passages known to exist as well, measuring 551 feet (169 meters) wide, 410 feet (125 meters) tall, and .6 miles (1 km) in length. The cave derives its name from the fact that the local deer population wanders inside to lick salt from the rocks from time to time, allowing visitors to spot these subterranean interlopers on occasion. Tour operators offer adventure travelers the opportunity to explore these caves with 3-day/2-night excursions into the strange, and oddly beautiful, underground world that lurks beneath the rainforest above.
Mammoth Cave National Park (United States)
Carlsbad Caverns isn't the only impressive cave system to be found in the United Sates. In fact, it isn't even the largest. That distinction goes to Mammoth Cave in Kentucky, which stretches for a mind-blowing 400 miles (640 km) of explored passages, making it easily the longest cave system in the entire world. It's carved limestone strata is surprisingly stable and beautiful, with twisting passageways and numerous chambers to wander through. Each year, additional tunnels continue to be discovered, leading deeper and deeper into the Earth. Many of those tunnels have yet to be mapped fully, and it remains to be seen just how massive Mammoth truly is. Park Rangers lead tours into the cave's depths on an almost daily basis, taking visitors on subterranean hikes that can last anywhere from 1-6 hours. Highlights include a trek down Grand Avenue past Frozen Niagara Falls and through the aptly named Fat Man's Misery. The more adventurous tours even venture far off the beaten path into caves that are seldom visited by travelers.
Cango Caves (South Africa)
South Africa has many attractions to help it lure visitors, not the least of which is the Cango Caves located in the Western Cape. While not nearly as large as the other cave systems on this list, the Cango Caves are none the less a spectacular sight to behold. The exact size of the place remains unknown, but it is believed to be approximately 15 miles (25 km) in length and drops as far as 900 feet (275 meters) below the surface. There are several tours that can be booked that take travelers into its depths, including an "adventure tour" which leads visitors deeper into the underground labyrinth. Be warned however, at times spelunkers must crawl through very narrow passages and up tricky rock formations while in low-light conditions, which can sometimes cause feelings of claustrophobia. Those who do brave its depths are treated to some impressive sights however, as the Cango Caves are well known for their excellent stalagmites and stalactites, which are on prominent display throughout all of the caverns.
Škocjan Caves (Slovenia)
A World Heritage Site, the Škocjan Caves of Slovenia are a fantastic destination for those looking to explore beneath the surface. Stretching for 6200 meters in length, the caves are both beautiful and sublime. In the depths of this system of underground chambers, the Reka River flows and disappears, making it a truly unique experience even or seasoned spelunkers. The caves are recognized for offering one of the largest unground canyons in the world, as well as a unique ecosystem that has developed within the caverns. Tours into the caves are offered in Slovenian, English, Italian and German, making it one of the most accessible for travelers.