A 25-ton blast door closing sounds like the end of the world — especially if you’re inside the shelter it’s protecting. There you are, walking down a long, quiet, dimly lit hallway, when you hear a loud bang followed by an unnerving silence. That door can’t be opened from the outside, and the sound of it closing makes you feel completely disconnected from the rest of the world. For decades, one of these doors lay hidden in West Virginia, protecting a state-of-the-art fallout shelter and a web of secrecy. In 1959, construction began on a new wing of the Greenbrier Hotel, a beautiful, upscale resort with rolling green fields and opulent white buildings. But the wing was really a front for the shelter, which was built underneath the hotel expansion by the US government to house members of Congress in the event of a nuclear attack on Washington.

The bunker was never used, but it was meticulously maintained just in case, and it remained a secret for three decades. Bunker staff lived secret lives as hotel workers, and the shelter was upgraded every few years with new furniture and up-to-date medical equipment. Then, in 1992, Washington Post reporter Ted Gus revealed its existence in a lengthy article. “For 30 years, its guests have come to play golf, to be massaged, to bathe in the restorative waters of the mineral baths,” he wrote of the Greenbrier, “while some of the men who repaired their televisions and brought them movies made all things ready for a darker world after this world.”

The shelter was subsequently shut down and now serves as a tourist destination. You can walk the halls and see the sterile decontamination showers and the old phone switchboards. It’s no longer a big conspiracy, but it did help the developers at Bethesda decide where to set the next Fallout game.

Over its last few entries, the post-apocalyptic Fallout series has laid waste to some major American cities. Fallout 3 showed players what a decimated Washington, DC would look like, while its follow-up imagined the bright lights of Las Vegas after a nuclear attack. Most recently, players were able to explore a wasteland version of Boston and its surrounding areas in Fallout 4. In this context, West Virginia seems like a strange choice.

Fallout games are great at showing familiar places that are completely destroyed; even if you’ve never been, you probably have an idea of what the Las Vegas Strip looks like, and seeing it reimagined in this new context is fascinating. The same goes for the Capitol in Washington and Boston’s infamous Green Monster. But for Bethesda, going somewhere less recognizable had benefits. “Most of the planet doesn’t really know a whole lot about West Virginia,” explains Pete Hines, Bethesda’s senior vice president of global marketing and communications. “So in a lot of ways, it’s a blank canvas where you’re not bringing a lot of assumptions.”

And the relatively unknown West Virginia proved to be a good fit for the game for a number of reasons. First, there’s the real-life bunker, which, if we’re being honest, sounds like a story out of Fallout lore, which is all about the strange and unnerving communities that developed in underground vaults following a nuclear war. “It’s kind of the original vault,” says Hines. That was the starting point, but Bethesda was also looking for other things. Fallout 76 is the biggest game in the series yet, and the developers wanted a location that was both large and varied. “We were looking for a place that had a lot of diversity in terms of the types of areas,” he says. “We wanted forests and heavily industrialized areas and towns. And size-wise, West Virginia was a really good fit to accomplish that in a neat way.” It’s also a region with its own unique folklore, including the iconic Mothman, which was reportedly first seen in the 1960s in Point Pleasant, 200 miles north of the Greenbrier.

I recently had the chance to play a few hours of the game, and the new location didn’t feel out of place at all. When it comes to wilderness, all Fallout games tend to feel largely the same: burnt-out forests filled with mutated animals. The post-apocalyptic version of West Virginia still had this, but it also offered a slightly different flavor. There were huge, mountainous areas that were a lot of fun to explore and really small patches of destroyed buildings in place of huge city settlements. There was plentiful farmland, and, at one point, I came across a capsized boat in the middle of a field. Other locations, like a county fairground, really make it feel like you’re in the remains of a small town. In real life, the mountains of West Virginia are often bathed in an eerie mist, and this feels perfectly at home in a Fallout game. (It’s especially ominous if you’ve played the “Far Harbor” expansion for Fallout 4, which takes place on an island full of radiated fog.)

One of the first things I did in the game was head toward the Greenbrier, which is still around today. It’s the kind of place where you need to wear a sport coat to eat dinner and you can walk past a hot spring on your way to an on-site golf course or church. In Fallout 76, it’s rendered with an impressive amount of detail; everything from the winding nature trails to the furniture in the lobby looks almost exactly as it does in real life. You can even read the commemorative plaques placed in front of famous old buildings. The main difference is that the hotel is staffed entirely by robots, and murderous bears are traipsing about the manicured lawns.

If you’ve been to the Greenbrier, it’s an eerie sensation to see a very specific place rendered so realistically and thrust into a very different context. But most people haven’t seen it, so for them, the West Virginia landmark will feel like one part of a very different type of Fallout location. It’s one you probably don’t know much about, and therefore, it offers the game’s creators more opportunities to play with expectations. “There’s some benefit to not having people already assume they know what a place is,” says Hines. For many players, that will mean the thrill of finding a huge blast door hidden under an unassuming luxury hotel.