Imagine, for a moment, that bitcoin really does hit $1 million.

You and many of your internet friends (whom you’ve only ever talked to via replies on Twitter, though they’ve still somehow supplanted your IRL friends) are now dummy rich. So what do you do with this newfound wealth?

Sure, you could buy out the Rainbow Room and enough drugs to down an elephant. Maybe you’d take a lavish vacation to the Caribbean. Perhaps you make some sensible moves and pay off a debt or two. You might even buy a lambo, as the old meme goes.

Or, more responsibly, you might begin outfitting your citadel.

In Medieval and Renaissance parlance, a citadel is a fortress whose lord typically had dominion over a small parcel of land and a rabble of vassals. For a Bitcoiner’s purposes, a citadel serves the same function as it did centuries ago: protection.

The concept of a personal Bitcoin citadel has emerged as a speculative evolution of self-sovereignty safety precautions like private key cold storage, fireproof safes for hardware wallets and the running of personal nodes. It has inspired a time traveler’s note on r/Bitcoin, served as an illustration for Bitcoiners’ vision of utopia and (of course) manifested itself in its fair share of memes.

As you find yourself in possession of this vast fortune, you’re going to want to protect it and yourself, but a regular house won’t do. No, you’ve got a taste for the lavish now, so if you’re going to wall yourself off to protect you and yours, it’s damned well going to be in an impregnable fortress that could survive Kingdom Come.

So, assuming hyperbitcoinization happens (or bitcoin just freaking rips to the moon), here are a few domains to consider.

1. Chateau Austin

Perched above the Lake of Austin in the Lone Star State of Texas rests a fortress befit for a medieval siege.

The 12,500-square-foot house sits on 3.68 acres of woodland. Concrete walls reinforce the home’s amenities (a pool, indoor sports area and an artist’s studio) belie a posh, contemporary dwelling that’s wrapped in castle-tier fortifications.

A 200-foot bridge traverses the forest canopy enveloping the plot to a boathouse astride Lake Austin. The lake is a definite plus with this property, which, along with reliable access to fresh water, also provides geographic protection.

Cost (at $9,300/BTC): 560.78 bitcoin

2. Columbia Island

About a 30-minute boat ride from Manhattan, New York, a self-sufficient private island waits for a new Bitcoining tenant.

On the island sits a four-bedroom, two-bathroom, 5,625-square-foot citadel, which is outfitted with solar panels, sewage, in-floor radiant heating and a reverse-osmosis water filtration system. It also includes a dock for smaller boats and landscape decking to prevent the island from flooding. Should be sustainable through the year 3,000.

Cost: 1,388.60 bitcoin

3. The Hard Luck Castle Mine

Want a Bitcoin citadel that can take a beating? Well, this 8,000-square-foot behemoth with 16-inch-thick concrete and reinforced steel walls might be the punching bag you’re looking for.

Isolated in the Nevada desert 200 miles from Vegas and another 150 from the nearest hospital, this modern-day fortress is outfitted for the worst. The thing runs on off-the-grid solar and wind energy, with a diesel generator for backup. It also has a 4,000-gallon reserve water tank, rain catcher system and a 3,000-gallon propane tank for heating.

By all rights, this citadel is nearly apocalypse-proof (it even has a watchtower).

Cost: 64.09 bitcoin

4. Silo Home in Saranac, NY

Ok, now do you want something that can really take a beating?

A vestige of the Cold War, this 1,600-square-foot home looks like an ordinary woodland cabin in Upstate New York. But underneath, an additional 2,300 square feet of living space occupies what used to be the launch control of a decommissioned nuclear silo. This converted grotto, complete with kitchen, jazz room, dining room, entertaining area and jacuzzi, sits 125 feet below the surface of the earth and is wrapped in steel-mesh reinforced concrete.

A 2,000-pound steel door leads to the defunct silo that used to house the weapons, which now, at 185 feet below the ground, can serve as a more than adequate fallout shelter in the event of some apocalyptic disaster.

Oh, and the property has a runway and hangar, as well — just in case.

Cost: 80.11 bitcoin

5. Hollywood Fortress

Nestled in the ridges of Los Angeles, California, this four-story, 7,700-square-foot hilltopper was built with military grade defensive structures (like missile-proof glass) and is outfitted with a network of safe rooms and “safe cores,” extra rooms which can be sealed off from the rest of the house.

The roof features a helipad for quick getaways, too, all in a home that includes an entertaining deck with a BBQ pit, a modern kitchen with a wood-fire pizza oven, a spa and other amenities that marry safety with luxury.

Cost: 427.26 bitcoin

6. Hogwarts (Seriously)

Did you know that the famed castle of Harry Potter lore is not located in the Scottish Highlands but, curiously, in Alcona, Michigan?

The 20,000-square-foot (literal) castle features 542 bedrooms, an absurd dearth of bathrooms (4.5) and overlooks 40,000 acres — plus, it’s perched on a craggy cliff face. Infused with all of the charm and magic that defines the fantasy series it represents, this fortress is honeycombed with secret passages and hidden alleyways — perfect for keeping intruders puzzled in a labyrinthian abode.

Cost: 10,681.54 bitcoin

7. Cave Cay, Bahamas

What could be better than a private island/citadel combo than one situated in the crystalline waters of the Caribbean?

Cave Cay, Bahamas, is a 222-acre private island complete with 2,800-foot landing strip and concrete dock that can accommodate up to 35 sea-faring vessels. It comes with a reverse-osmosis water purifier and diesel generators and can also support solar power for optimum self-sufficiency. The main house, which offers a panoramic view of the island, will soon be accompanied by a club house, restaurant and guest accomodations for your posse, too.

Cost: 6,408.92 bitcoin

So, if you can’t find your post-apocalyptic (or just post-moon) personal Bitcoin citadel among these contenders, maybe siphoning yourself off in complete isolation from society to live the utopian ideal of self-sovereign money just isn’t for you. Or maybe you’re just waiting for that space station listing…