We know from experience that no matter how isolated or dark or cold the environment, there is always something that lives there – more than one thing, usually, that just thrives living the introvert life.

The deep sea, outer space, and sure, Movile Cave – where nothing went in and nothing went out for over 5 million years.

The cave is situated a few miles from the Black Sea coast in Romania, and is one of the most isolated places on the planet. Around 5.5 million years ago it was sealed off from the rest of the world by thick layers of clay and limestone.

It was discovered by researchers in 1986, and is now guarded around the clock due to the totally unique biology that exists inside.

Also, with 100 percent humidity, a toxic atmosphere, and a total lack of sunlight makes it a less than hospitable vacation spot.

Scientists have identified 53 invertebrate species that don’t seem to mind, though; 37 of the species are not found anywhere else on earth.

They’re spiders, water scorpions, leeches, and centipedes, among others. Most of them have no eyes or pigment, among other adaptations to the environment.

Since there is a total lack of sunlight in the cave, the food chain depends on chemosynthesis as opposed to photosynthesis. The bacteria inside oxidize the abundance of methane and sulfur in order to produce nutrients that are eaten by critters on the ground.

It’s the only food chain of its kind ever found on the land, and a 1996 research paper explains why that’s interesting.

“The Movile Cave system is similar to deep sea vents in having a chemoautotrophic food base and a diverse biota. However, the cave system appears to lack the symbioses between chemo-autotrophic microbes and animals so characteristic of deep sea vent communities.”

Biologists continue to study the cave, so there’s probably a lot more to be discovered.

It the invertebrates there are anything like the introverts I know, they’re probably already wishing they could pick up and move to avoid the crowds.

Thought that was fascinating? Here’s another story you might like: Why You’ll Never See A Great White Shark In An Aquarium