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.
A secret storage in a staircase can be a great hidden storage for bulky things that look unflattering when stored in full display. It’s the same space under stairs only hidden and accessed from the floor in the staircase. At: The Bottom Of The Stairs