A knight can visit every square on a chessboard exactly once without ever landing on the same spot twice.

The Knight's Tour is a famous problem in math and computer science. A standard chessboard has 64 squares. A knight moves in an L-shape, jumping two squares in one direction and one square sideways. To solve the tour, the knight must land on every square exactly one time.There are two types of tours. A closed tour ends on a square where the knight could jump back to its starting spot. An open tour ends on a square that is far away from the start. Mathematician Leonhard Euler studied this problem in 1759. He used symmetry to find many different solutions.Scientists have calculated that there are over 26 trillion possible closed tours. This number is even higher for open tours. In 1823, H. C. von Warnsdorff created a rule to help solve the puzzle. His rule says to always move the knight to the square that has the fewest possible next moves.Today, computer scientists use this puzzle to test how fast computers can solve problems. It helps students learn about graph theory and how to write code that explores many options. The challenge can also be done on larger boards or even 3D shapes. It remains a popular way to teach logic and search patterns.