The Grand Canyon. Pike Place Market. Mount Rushmore. New Orleans’s French Quarter. Waverly Hills Sanatorium. The Golden Gate Bridge. This list includes some of the top-visited attractions in the United States. Yet, if you look closely, one of these destinations is not like the others. A visit to a haunted Sanatorium may not seem like a great place to get some R&R, but this is a trend of destinations that people are dying to visit. Make sure to pack your security blanket for this trip because, well, it’ll haunt you if you don’t.

The term “paranormal” describes something that science cannot explain. The booming paranormal tourism industry covers lots of ground. Ghosts, extraterrestrials, witchcraft, demons, sites of macabre significance, and clairvoyance are popular features. Why are we drawn to these scary topics? And why is the curiosity growing at a chilling rate? What’s the motivation for owning a piece of creepy history? (And actually admitting “something ain’t right”).

Paranormal tourism isn’t a modern concept. Since the beginning of time, people flocked to sites of supernatural happenings. Even the Ancient Greeks would cross dangerous oceans and terrain to visit the Temple of Apollo, where the Oracle of Delphi, a fortune teller, resided.

Today, loads of people go to great lengths to experience the paranormal. These adventurists drive hundreds of miles into remote corners of the English countryside and America’s heartland in hopes of getting a glimpse of a cropcircle. An estimated 50 million people have boarded and toured the infamously haunted ship, the Queen Mary, harbored in the port of Long Beach, CA.

The cursed Robert the Doll in Key West, FL has almost 15,000 “likes” on his Facebook page and receives visitors from around the world. Yes, A DOLL. Also, if the fact that a doll has more likes than you on Facebook stings the ego a bit, know you’re in good company.

Heck, just last month, a million people threatened to storm Area 51 in an attempt to reveal the aliens allegedly housed there. In reality, a few hundred actually showed up. Although these Naruto runners wanted a meet and greet with E.T., military personnel made it clear admittance was not an option. The discouraged mob took it in stride and jokingly requested the release of “just one little alien." Spoiler alert: they didn’t release any extraterrestrials. What the mob did accomplish, though, was a demonstration of how Paranormal Tourism is booming. And it’s growing at a truly frightening rate.

In a study conducted in 2016, researchers found 38% of people partook in paranormal activities as part of their vacation (like a ghost tour or haunted house). The study found a shocking 44% of people’s vacation destinations WERE the supernatural sites.

America Haunts, a trade association that manufactures haunted houses for entertainment, estimates there are more than 1,200 haunted houses in the United States. Even more shocking is that these houses of horror bring in more than $500 million each year. The industry has doubled over the past 10 years.

But, why are we so drawn to the dark, unexplainable, and spooky? Much like a home-alone heroine to an unfinished basement when she hears a spooky sound. And can she just turn on the lights rather than relying on a flashlight that is OBVIOUSLY going to run out of batteries the second she’s in the deepest belly of said basement? But I digress...

Psychologists have several theories. One theory categorizes stimuli like haunted houses and ghost tours as “controlled” fear. We’re scared, but know we’re not actually in legitimate danger. There’s also a physiological effect that happens when we feel threatened. Our hearts pump faster, our senses heighten, and our bodies tense, ready for what may jump out. Only when we realize there isn’t any danger do our bodies respond with a dopamine-induced rush of relief. It’s like a rollercoaster, literally and figuratively.

Another theory is that we, as a human race, are just curious. Our world is a lot easier to cope with and thrive in when it makes sense to us. The fear of the unknown is a concept as old as time itself. When we don’t fully understand something, we naturally want to experience and explore it more.

We crave a sense of understanding with our constant exposure to media and entertainment. Ghost hunting shows, Bigfoot hunts, and even the Twilight saga encourage us to consider the intangible and unprovable more often.

Small cities like Amityville, NY of the Amityville Horror fame and Point Pleasant, WV for its elusive Mothman are on the map primarily because of the seemingly unexplainable events that occurred there. Even entire towns considered haunted. Gettysburg, which hosted a three day Civil War battle that took the lives of an estimated 51,000 men, is considered especially haunted.

When on the hunt for proof of the paranormal, consider compounding your chances of capturing evidence by staying in a haunted hotel. Some hotels who embrace their, um, “reputations” have found it to be a pretty good money maker for the property.

For example, The Crescent Hotel, in Eureka Springs, Arkansas, was built in 1886 as a resort for the wealthy. After mismanagement, it had a stint as a college. Finally, in 1937 a millionaire named Norman Baker purchased it. He turned it into a hospital and health resort and, despite his complete lack of a medical degree (or really any knowledge of anatomy or how the human body actually works) likened himself to a doctor.

He claimed to cure people of diseases like cancer by prescribing the Ozark’s spring water as a treatment at his “health resort." It doesn’t take a storytelling genius like Stephen King to see where this is going. Long story short, a bunch of people died and are said to still be enjoying the Crescent’s amenities.

The Crescent noticed their occupancy climbing with each paranormal investigation. The ghost tours alone bring in hundreds of thousands of dollars to the property each year. (This doesn’t include the “Spirit of the Crescent” room special you can get which includes a room at the hotel, two tickets for the ghost tour, a ghost coffee mug, and two ghost shirts for a price of around $300. A bargain, if you ask me.)

To boost occupancy during the offseason, owners Marty and Elise Roenigk host “Paranormal Weekends." The exclusive weekend gives guests access to Mr. Baker’s in-building morgue (no thank you) and the use of ghost hunting equipment. While those weekends before struggled to get 20% occupancy, they now have a substantial waiting list.

Haunted hotels are spooky, yes. Now combine violent criminals, incarceration, poor living conditions, brutal treatment, and an electric chair named “Old Sparky." This gives yourself a lot of ticked off spirits who are said to still be serving their sentences. West Virginia State Penitentiary in Moundsville, WV was a prison from 1866 to 1995 that housed 450 prisoners. That number soon climbed to over three times that, forcing 3+ prisoners to share a single 5x7 cell.

Records were pretty “meh” back then, but experts estimate the inmate deaths to be well over 1,000. A small portion of around 104 done by mandated execution. Most of the deaths were at the hands of fellow inmates. Inmates reported hauntings as early as the 1930s and continue to this day. Tales of seeing “The Shadow Man”, whose name is a pretty accurate description of his looks, and the ghosts and disembodied voices of other prisoners and guards, are a shockingly common occurrence. The old penitentiary continues to lure over 12,000 visitors through its doors each year, and this number is climbing.

Paranormal tourism doesn’t always revolve around the undead. Let’s unpack Easter Island, for example. It is 2019 and it’s still a mystery how the 1,000, fourteen-ton, thirteen-foot high statues, or Moai, got there. This is especially curious considering they were carved around the year 1,100 AD, limited to manpower and rope as tools. Oh, and did I mentioned they were being moved not just a couple of feet, but upwards of eleven miles? There are many theories, but none that are universally accepted. Some say it literally took a village. Others argue extraterrestrial intervention. Call up Fox Mulder, we got a live one!

Whether you believe it’s extraordinary teamwork or a leg up from aliens, there’s one thing no one can argue... People can't stop themselves from visiting. The island, which is roughly the size of Washington D.C., is one of the most remote, but inhabited islands in the world. Despite its small size and proximity to, well, nothing (the closest continental point is over 2,000 miles away), 100,000 people flock there every year to say “Oh, hi!” to the Moai.

Paranormal Tourism isn’t only going to continue to grow. So too will the spirits, ghouls, ghosts, and mystery that drive its popularity. Owners of haunted and mysterious sites stumbled upon a lucrative business. If you’re brave enough to admit to the paranormal activity aloud, that is. So grab your holy water, some sage, and the nearest Ouija board to watch the tourists (and cash) flow in. The rest of us will continue to be baffled and intrigued (and scared out of our minds) at what can only be explained as unexplainable.