Minted and crowned

Imagine if you can the greatest bank vault…
Ribbed door; heavier than any mountain wall.
Where no safecracker can by time lock default:
Gain access… The glorious treasures, enthral.

Doors with a time lock, on all deposits…
One, once you enter, there’s nothing to be found.
No jewels, paper money, or trinkets
Just your own coinage minted and crowned.