The Weird Truth About Hang Son Doong, The Cave With Its Own Rainforest Inside

For all of history, caves have captivated humanity. We have used them as fortresses, dwelling spaces, canvases, and scientific backdrops. We have found countless new species and ecosystems preserved between their limestone walls. And as far and deep as caves go in our history, there is perhaps not one quite so impressive as Vietnam's Hang Son Doong.

Believed to be the largest cave on Earth, Hang Son Doong is located in Quang Binh Province and bursting with life outside the human race. In fact, Discovery reports that it's so vast, only a handful of human beings have been brave enough to venture between its walls. What awaited them 200 meters beneath the Earth's surface is an altogether breathtaking ecosystem that has gone on almost completely undisturbed for what scientists estimate to be about 3 million years. The coolest part of all? Hang Son Doong is so unfathomably large that it has its own rainforest.

A lush, warm rainforest is majestically tucked inside of Hang Son Doong where it flourishes thanks to the light enveloping it from above and the water that travels through it. According to BBC, the rainforest has a way of recycling its moisture, effectively watering itself in the process, and giving way to an awe-inspiring ecosystem that exists hundreds of meters beneath our feet.

According to CNN, the rainforest situated inside of the world's largest cave is so unique it even has its own weather patterns. It is a world within a world that harkens back to ancient times. Scientists have already discovered seven new and unique species dwelling inside the cave: Translucent and eyeless, these underground organisms are reminiscent of prehistoric Earth creatures (via Nature World News).

Hang Son Doong is estimated to be at least 1.35 billion cubic feet, complete with rivers and underground trails, CNN reported. In addition to housing its own rainforest, weather, and ecosystem, the cave is also home to not one but two jungles.