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Germany’s Neuschwanstein Castle certainly looks the part. So does the Tower of London. But an ammunition bunker in South Dakota — especially one advertised as a place to go “glamping” — isn’t what one normally thinks of as a castle.
In his new book, “Castles: A Fortified History of the World” (Viking, Nov. 3), historian Dan Jones makes room for all of them.
He starts with the familiar idea of a fortified residence, then considers buildings whose defenses became less important than their grandeur. Rather than insist on one architectural checklist, Jones concludes that “a castle can be many things” — from Bronze Age walled cities in the eastern Mediterranean and the homes of British monarchs to modern underground shelters and Mark Zuckerberg’s Hawaiian compound.
“Safety, status, and luxury are things that can best be enjoyed from behind strong defenses in secure locations,” Jones writes. “Protecting one’s person, family, and property is the starting point of projecting power.”
How much defense a castle actually needs depend on who builds it. For some wealthy Americans, the European look was enough.
George Washington Vanderbilt II’s 250-room Biltmore estate in North Carolina took inspiration from France’s Chateau de Blois. When Vanderbilt welcomed guests at Christmas in 1895, they found a banqueting hall with a carved Gothic throne and a library containing 20,000 books. There was also a swimming pool and bowling alley.
“Besides a collection of historic armor that included Japanese samurai pieces dating to the age of the Tokugawa shoguns, there was nothing remotely defensive about the Biltmore,” Jones writes.
Still, it gave other rich Americans something to aspire to. As Jones puts it, “The leading men of the new industries founded dynasties and built dynastic seats to match.”
In the early 1900s, hotelier George Boldt built a six-story residence on Heart Island in the St. Lawrence River, complete with conical towers and medieval-themed buildings. In 1914, in Connecticut, actor William Gillette, famous for playing Sherlock Holmes, constructed a castle equipped with secret passageways and a mirror-based spying system.
Gillette was particular about its future ownership. In his will, he warned against leaving it to “some blithering saphead who had no conception of where he is or with what surrounded.”
William Randolph Hearst went further in bringing Europe home. At his California castle, constructed for decades throughout the first half of the 20th century, the newspaper magnate’s bedroom incorporated a painted 14th-century ceiling and doors imported from Spain.
Photographer Cecil Beaton recalled arriving at the estate. “We caught sight of a vast, sparkling white castle in Spain,” he wrote, as Jones recounts in his book. “It was out of a fairy story.”
At Disneyland, Sleeping Beauty Castle turned the European fantasy into a commercial attraction. “Castles had always been buildings where function and imagination commingled; here, imagination was everything, and what function lay beneath was concerned with profit and not war,” Jones writes.
For today’s buyers of massive homes, keeping people out remains a selling point.
Take Mark Zuckerberg’s Koolau Ranch on the Hawaiian island of Kauai, which covered 1,400 acres in the 2023 reporting Jones cites. Plans called for dozens of bedrooms, kitchens and entertaining rooms, along with a few precautions against unwelcome visitors.
“Planning documents also suggested it will have an underground shelter, blast-resistant door, private energy and water supplies, and food-production capacity,” Jones writes. By July 2025, the estate had grown to more than 2,300 acres, with plans for additional buildings.
Meanwhile, Peter Thiel has been trying to build a massive luxury lodge in New Zealand overlooking Lake Wānaka and designed with a grass roof to help it blend into the hillside. The roughly 1,080-foot-long complex would accommodate up to 30 guests, with a separate owner’s residence and a meditation building. But planning authorities rejected it in 2022, finding that its size would dominate the protected landscape and that it’d be too visible from a nearby public walking track. The Environment Court rejected his company’s appeal in May 2024, concluding that proposed tree planting wouldn’t adequately screen the buildings.
But super secure, secluded settings aren’t just for the filthy rich. “Twenty-first-century fortified compounds are also currently being developed and marketed to the merely moderately wealthy,” Jones writes.
At Vivos xPoint, a former Army munitions depot in South Dakota, buyers can choose from 575 bunkers buried beneath thick layers of soil, with 400 feet between neighbors. Prices begin at around $55,000 before outfitting, which the company says can turn your shelter into “a very chic glamping bunker on a barebones budget.”
Modern shelter owners face their own uncertainty about what might await them outside. Jones describes compounds with independent water and power supplies, medical dispensaries and a year’s stockpile of fuel and toilet paper. There are even detention centers. Apparently, surviving the apocalypse doesn’t mean everyone will get along.
“What sort of world would be left for the inhabitants of such a fortress to rule over, should such a war break out?” Jones asks.
The Vivos sales pitch makes the preparations sound manageable. Think of a long camping trip, it suggests, with concrete and steel to protect you.
The difficult part is knowing when the trip ends.
