Forget about Sudoku – that is child’s play when compared against the Isis ball. Touted to be the most difficult puzzle of all time, this interactive mind puzzle requires you to open up the alloy ball. This ball is made from various layers that are covered in ancient Egyptian hieroglyphics. No two Isis balls are the same as they all require a different combination before they can be opened. Once your cerebrum has worked hard enough to crack the combination, you will be rewarded with a special key inside that comes with an engraved number. This key can be used to open one of the Isis golden pyramids that are stored throughout secret locations in the U.K., containing a loot of gold and silver coins that are worth more than £500. You could say the Isis ball is certainly much harder to crack than winning a ticket to Charlie’s Chocolate Factory. Unfortunately, each Isis ball will set you back by £99.95.