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Panic Room

Location: Everywhere, but they seem to be especially popular in Los Angeles.

The safe room or panic room is like a modern answer to a fallout shelter, and are found in homes of the rich, famous and hated personalities. It’s typically a windowless space with a fortified door, communications equipment to call for help, and supplies.

With no less than 103 rooms, five swimming pools, and 250 tons of marble, including a heated marble driveway, the neoclassical mega-mansion Updown Court, pictured here, might be more likely to be the cause of the end of the world, rather than a refuge to ride it out. But it does offer a panic room that is probably big enough to host a dance party, and some other handy features for any emergency-minded buyer with $123 million to burn, including a 24-hour security lodge, an underground garage, a private helipad, and 58 acres of private woodland.