treasure chest

noun3

1. •
   A chest filled with treasure, especially one used by pirates, etc.
2. •
   (figurative) Any source of something valuable or beautiful.
3. •
   A treasury, especially a state or royal treasury.

   • They acted the part of a sponge for the Royal Treasury, they gathered up all the floating money of the country, to be squeezed from time to time into the king’s treasure-chest […] — 1892