Level: Castle
After you take the first opportunity to unlock the drown 19 times achievement, you will need to climb on the house and use the 3 lanterns to swing across to the next area.
Once on dry land again look to where the bridge joins this area next to the house on the left as you look at them both. Climb up on the wall here, then jump on the nearest house. Continue along by jumping to the next house and then on the walkway on the wall. Follow the path until you climb up twice more in quick succession and here you will find a catapult facing the tower with a bell.
Move the catapult away from the edge so it's approximately 3 times the width of your guy/gal. Wind it up and load it up, then use the lever and you should hit that bell no problem.