(NewsNation) — From everyday Americans to celebrities, doomsday preppers are stocking up for fears of the end of the world, nuclear war, a major economic collapse or World War III.

Now, real estate speculators say there are plenty of people concerned about the future to buy properties in bunker communities.

Doomsday bunker in Indiana

NewsNation senior national correspondent Brian Entin visited an “elite” bunker that’s 10,000 square feet and sleeps up to 80 people. A company called Vivos owns the bunker as well as several other underground shelters all over the U.S. The bunker Entin visited is located in Indiana, but NewsNation agreed not to disclose its exact location. The cost of a seat in the shelter? $30,000 per person.

The bunker boasts a movie theater, kitchen, living area, several bedrooms and an area for pets and gardening.

“We have one that has an underground lake pending — a 600-foot-long lake. We’re going to put row boats in it. It has a beach on one end. We’re going to have fish in there. With illuminated water, it’d be like Disney Land ‘Pirates of the Caribbean’ or something, you’d be underground,” Vivos owner Rober Vicino said regarding a bunker that’s under construction.

He added it will also feature “a golf course, all sorts of sports, every sport you can think of — shooting range, archery.”

What is doomsday prepping?

Doomday prepping has been defined as: “The management of stockpiled household items in anticipation of market disruption.”

There are different kinds of preppers out there, including doomsday preppers, climate change preppers, wilderness survivalists and homesteaders. Each have their own preferences and distinctions.

Preppers are people who make preparations to survive without government assistance in the event there is a disaster. They may learn survivalist skills as well as stockpile supplies such as food and ammunition.

Who is doomsday prepping?

In the past year, Finder.com says 39% of millennials and 40% of those in Generation Z reported spending money on prepping. But they’re not the only ones diving into the prepper lifestyle.

OpenAI co-founder Sam Altman and celebrities Ryan Seacrest and Josh Duhamel are reportedly into prepping, too. Meta founder Mark Zuckerberg is also building a massive Hawaiian compound complete with treehouses, dozens of bedrooms and even an underground bunker, according to an investigation by Wired.

Roughly a third of the adult U.S. population reportedly dropped $11 billion in the past year or so on emergency preparedness.

Doomsday bunkers

In December, Entin visited a former Army base turned bunker community in South Dakota that’s off-grid and built to be self-sufficient.

At Vivos xPoint, some people have a plane full of gas to get them to their bunkers at any moment. Some of the bunkers have generators, a bomb blast door, gun safes, an electrical room and storage for food, along with bedrooms and bathrooms.

The South Dakota property of more than 530 bunkers is built to be self-sufficient. Out of all the $55,000 bunkers on site, about 200 have sold and sales have been picking up.

In the video above, NewsNation national correspondent Brian Entin visits a former Army base turned bunker community in South Dakota that’s off-grid and built to be self-sufficient.

Many countries in the world, including the U.S., advise people to prepare to survive for three days without assistance from authorities in the case of an emergency.

As far as the popularity of the practice goes, Finder.com says nearly 30% of surveyed Americans reported taking steps toward emergency preparedness in 2022, which represents roughly a 25% increase compared to 2017.

NewsNation’s Caitlyn Shelton and Sean Noone contributed to this report.