The Lonely Knight

This is a chess puzzle. We have created several chess games/puzzles. That was the first. A fun little game for chess fans like us.
The rules:
Please help the Knight to go from the green castle to the blue castle. Notice that: There are 4 lines of square columns between the two castles that have to be passed. The only way to pass is to touch all the squares once & end up with the same spot you started with. The Knight step is like a knight step in chess.