Mushroom Kingdom Treasury
From the Super Mario Wiki
The Mushroom Kingdom Treasury, or just the Mushroom Treasury, is, as its name implies, the treasury hall for the entire Mushroom Kingdom government. Billions of Gold Coins are housed in the treasury's many rooms and compartments.
In The Adventures of Super Mario Bros. 3 episode "Crimes R Us", Bowser felt that his Koopalings had pulled enough "small crimes", and figured that it was time for them to pull the ultimate crime: stealing one billion gold coins from the Mushroom Kingdom Treasury.
While the Koopalings prepared to break into the treasury using a Bob-omb, a Chain Chomp, a Fire Snake and a Ptooie, Crimewave Clyde had recruited his former foes Mario and Luigi into helping him stop the Koopalings. Arriving at the treasury before the Koopalings finally broke in, Clyde and the Marios waited for the Koopalings to discover them, only to for them to be tied and returned to the Doomship, along with a Bob-omb surprise. With the Koopas gone, the robbery was foiled.