There are two separate ways to complete the Keep. It's generally one of the easiest sections in the game after the symmetry island.
The keep is the castle in the middle of the field between the town and the marsh.
As you enter you will see a bunch of cut hedges, and can walk through towards a puzzle than you don't complete with your cursor but actually with your footsteps.
Each puzzle opens a new door.
Puzzle 3 - this one is a bit tricky. You have to do it in reverse as there is a blocker in the path.
Stand at the end of the puzzle and from a distance, reset the puzzle on the board. Then start it from the end and go backward
Puzzle 4 - This is a symmetry puzzle but u only need to walk one side.
Climb the tower and complete the final puzzle to activate the laserMaze Side
The other option is to complete the 4 mazes in the front of the keep tower.
Moving in a clockwise fashion
Maze 1 - draw the only possible path
Maze 2 - draw the path that is not blocked by tall grass
Maze 3 - draw the path that has no sound of breaking branches as you step
Maze 4 - draw the path that exists on the panel and in the maze, the rest of the directions don't exist in both
Finally climb to the top of the tower and complete the maze by memorizing your answers to all the mazes on ground level. It may help to draw this with a pen.