If you mean leave your money in a safety deposit box, most casinos have them available but may be fully used. Some hotels have safes in the room you can leave cash/valuables. Check with your hotel/casino.

@thamster ty man,but in london for example u just deposit the money/chips and it's like a bank,they see how much it is and they give u a recipt.when u want it back u go with the recipt and that's it.