This puzzle is rated 3 star (hard).
Here is a classic puzzle from the Canterbury Tales, where a prisoner has to come up with a puzzle to be pardoned for his crime - and this was his creation.
Draw the grid above, making sure to leave the gap (missing line) at the bottom centre of the grid.
Starting at the prisoners location (the black square) make 15 connecting lines that do not cross and pass through all the other blank squares.
Check the solutions page for the correct answer.