This is for the serious puzzle fanatic.
Seven intriguing mind puzzling games in one box.  Based on the games played in the Bastille Prison during the French Revolution.  This will keep your intrest for quite a while.  It took my wife two solid weeks to solve all seven of them.  Marbles are stored within the box with an easy push through opening in the top and a slide to release the marbles on the side of the box.