The Tower of Hanoi also called the "Tower of Brahma" is a mathematical game or puzzle. It consists of three rods, and a number of disks of different sizes which can slide onto any rod. It looks like a puzzle game but it's hard as solving Calculus questions. The puzzle was became famous by Edouard Lucas in 1883. There is a story about an Indian Temple in Kashi Vishwanath contains three posts in it surrounded by 64 golden disks. Brahman priests moved these disks. According to the legend, when the last move of the puzzle will be completed, the world will end. It is not clear whether Lucas invented this legend or was inspired by it.

Harmony PBL: Tower of Hanoi