As a regular writer of articles that discuss casinos, I am sometimes asked, "Where do casinos keep their money?" While all casinos are different, they all go through the same steps to keep their money as secure as possible.
Never discuss this topic inside of a casino. If you start talking about the casino's vault, or procedures for securing money, you open yourself up for becoming a focus of security and could be called off the gaming floor for questioning.
All of the major casinos in the world use some kind of high-security vault in which to secure their money. In all cases, these vaults are well-protected areas that would put some high-security government complexes to shame.
Sometimes you will notice that all of the cashier cages in a casino are located in a circle in the middle of a casino. In some cases, the vault is either located in the middle of these cashier cages, or they are located underground directly under the cages.
There are many casinos that will place their vaults underground, just like in Ocean's 13. It has been proved that vaults are much easier to secure the further it is from the action going on around the gaming floor. Some casinos might have vaults that are multiple levels below the gaming floor.
There have been temporary cases in which casinos have taken the money out of the vaults to movie somewhere else. This information is usually kept only to a few individuals, and will take years to ever make way to the general public.
There have been a few instances in which the money from casino vaults have been moved to secured rooms inside of the hotel attached to the casino. This is usually done only for a night or two while updates are being made to the security system of the casino vault. Patrons in the hotel have no clue that there are million of dollars in the next room (along with a group of heavily-armed guards).
When Howard Hughes was in his isolation inside of his Las Vegas hotel, at least once, he had all of the money from the casino vault transferred to his room. He never gave the reason for this transfer, and according the accountants, all of the money was accounted for once it was sent back to the casino vault.
During high-profile professional poker tournaments, some of the money from the casino vault will make way up to the room where the tournament is held. It is tradition to have the winner's total take from the tournament represented in person by stacks and stacks of real money. Even though this money is out in the open, it is still well protected.
The casino vaults in the world are some of the most impervious locations to be found anywhere. The casinos were not built buy people that were not able to keep their money secure. The casinos were built by those that realize that their main asset is the money held in the casino vault.