apocalypse bunker made from a former missile-silo, these could be a good idea,purchase them around the country if your a millionaire and have nice rest points for you travels during the z end of days lol(also can be used as an minecraft house I'd
secret door to an underground storm shelter/panic room/hid out in the kitchen island! Best secret passage ever! Definitely a dream home feature! (would also be good if someone broke into your house and you had to hide somewhere) Zombie apocalypse.