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 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, as there is plenty to be seen beneath it as well.
In fact, some of the most amazing sights that nature has to offer can be found inside the Earth's countless caverns. With that in mind, here are five 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).
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 adventure traveler.
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 them 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, subterranean world that lurks beneath the rainforest above.