Kentucky has something unique, but it’s not fried chicken, country music or the Derby.

Kentucky’s unique wonder is Mammoth Cave and is found underground about 30 minutes North of Bowling Green.

There are 375 miles of discovered pathways in it, and more to be discovered, making it the most extensive known cave system in the world. The next largest cave is Jewel Cave in South Dakota at 140 miles long.

This natural wonder is made of layers of limestone with sandstone above keeping it intact, said Vicki Carson, public information officer for Mammoth Cave National Park. The rainfall on the limestone creates underground waterways.

People started exploring the cave about 4,000 years ago, Carson said.

In the late 1700s, settlers came and began a community around the cave. The first public tours started in 1816, led by three slaves: Matt Bransford, Nick Bransford and Steven Bishop. They were also free to explore to cave on their own.

“They perhaps had more freedom underground than they did on the surface,” Carson said.

In 1941 the cave and some of the surrounding areas above ground became a national park. Currently, 14 of the 375 miles of discovered cave are publicly toured.

The cave isn’t just for tourists; it’s also home to 130 known species.

“It’s a true oddity,” Carson said. “There are so many unknowns about the cave.”

The Kentucky Cave Shrimp, small fresh-water shrimp, are one such species, Carson said.

Also a new form of rock-eating bacteria, lithotrophic, was just discovered. Scientists are wondering if lithotrophic influenced the formation of the cave.

About 740,000 people visit the park every year. In the summers, about 3,000 to 4,000 people visit a day, Carson said.

Chris Groves, professor of geography and geology, takes his undergraduate students on a cave tour every semester.

Somerset Sophomore Nathan Holton came on the tour with his girlfriend who was in the class. He had been to the cave before in high school.

“I think you don’t have to be a cave person to enjoy going down into caves,” Holton said.

He’s six-foot-five inches tall, but his favorite part of the tour was “fat man’s misery” – a very narrow and short part of the cave.

Western’s relationship with Mammoth Cave is two-way, Groves said. The cave is a laboratory for students and Western produces scientists and researchers to work in the cave.

Western has a graduate studies program in cave research that draws students in from around the country because Mammoth Cave is so close by.

“There’s a relatively constant stream of scientists from around the world coming to Western and interacting with our students,” Groves said.

Scientist Xavier Beuchat, a visiting graduate student from the University of Neuchatel in Switzerland, is researching agricultural pollution while he’s here.

He’d learned about Mammoth Cave while in school back in Switzerland.

He said he realized how different it is from Swiss caves upon touring it. In America, caves are more commercialized. In Mammoth Cave, there are built pathways and even a restroom inside the cavern.

The caves in Switzerland are more vertical and not as open to the public. He likes this because tourists can’t mess things up.

He said he finds the influence of water in caves to be fascinating.

“A little drop can make a big cave,” he said.

Reach Nina Bosken at diversions@chherald.com.