be like Fort Knox

be like Fort Knox

To be inaccessible, usually because the item or place in question is locked or guarded. Fort Knox is a military site in Kentucky where stores of gold are kept. The kids are home by themselves, but don't worry, the house is like Fort Knox with all the security cameras. I can't get into the safe, it's like Fort Knox!
See also: fort, Knox, like
Farlex Dictionary of Idioms.

be like/as safe as Fort ˈKnox

(about a building) be strongly built, with many locks, strong doors, alarms, etc. so that it is very safe and difficult for thieves to enter: This home of yours is like Fort Knox. Financially she’s as safe as Fort Knox. Fort Knox is a military base in Kentucky where most of the US’s store of gold is kept.
See also: fort, Knox, like, safe
Farlex Partner Idioms Dictionary
See also:
  • be like/as safe as Fort Knox
  • fort
  • Knox
  • item
  • be an item
  • locked down
  • trade in
  • trade (something) in for (something)
  • trade (something) in on (something)
  • close the door to (one)
References in periodicals archive
Last night, Burley said: "There will not be a third time because my house is going to be like Fort Knox."
Burley in pounds 30k burglary