The Guardian – Alex Bellos
“Today’s puzzle is for escapologists. Imagine you are in a grid 100 squares long and 100 squares wide. (The grid is fixed to the compass directions: up/down is N/S, and left/right is W/E.) On each square of the grid, there’s an arrow. Each arrow is pointing either N, S, W or E. Choose any square. That’s your starting position. Now the game begins.” (more)