EUREKA SPRINGS, Ar. – If you ever visit downtown Eureka Springs, you’ll probably do a lot of walking. But what’s underneath those streets might surprise you.

OzarksFirst recently went on the Underground Eureka Walking Tour. Head tour guide David Riordan showed a crew around.

“There are three-quarters of a million tourists who come to Eureka Springs every year, and most of them know absolutely nothing about it,” Riordan said. “What we like to teach people is the history, which includes this incredible story of the underground system. We want to advise them, educate them about the amazing history here.”

Riordan says back then, the area didn’t have any trees. As a result, Eureka Springs would have flooding problems when it rained. Most of the time, the town was under five to 10 feet of water. So, the city used 12 to 14-inch wooden beams to raise their buildings, street levels and sidewalks over the original tunnel system.

“Spring Street, Main Street, Mud Street and Leatherwood Creek. Basically, the whole town is up on stilts with these tunnels filtering water down underneath it. It’s pretty ridiculous that a town would be here at all.”

Take a look at what’s under Main Street.

Seattle, Washington also has an underground system. Riordan tells OzarksFirst nothing can compare to Eureka’s though.

“There’s nothing like this. Really this is the only town in the world that was built because of magic water. We’re in the middle of nowhere and thousands of people came here to seek the magic cure.”

Only a small portion of Eureka’s underground is open to tours. It’s a decision that was made with the public’s safety in mind. Four years ago, a tunnel collapsed underneath a parking lot on Main Street. It created a hole about 20-feet deep. No one was hurt.

“There’s no foundation. Cars fell in. It was a big mess. It basically just opened up the underground, and anybody could go in. We had homeless people go in there. They started making fires, and so [the city] had to become very draconian about it. For now, it’s illegal to go in the underground except for the sections [the tour shows] you. Whether you live in Springfield, Orlando or New York, everything falls apart. That’s the way the world is. It just happens a lot faster here. So, we have to be constantly vigilant.”