Walkway leading into the Big Room, Carlsbad Caverns, New Mexico, USA

© Doug Meek/Getty Image

Carlsbad Caverns, New Mexico, USA

With deep rocky canyons and high ancient sea ledges, Carlsbad Caverns National Park in New Mexico, USA, boasts some of the most unique rock formations in the world. Hidden beneath its desert scenery are more than 119 caves—formed when sulfuric acid dissolved the surrounding limestone. This national park, founded on this day in 1930, is also home to North America's largest underground chamber—the Big Room. From colossal stalactite formations hanging like chandeliers to stalagmite structures reaching for the ceiling, every nook and cranny is a masterpiece crafted over millions of years. This UNESCO World Heritage Site also organises events like bat flight viewings, which allow visitors to watch thousands of bats as they swoop in and out of the cavern. So, are you ready to explore the depths?