I enjoy puzzles and riddles quite a lot. That is why I when I why run a game as a Dungeon Master or game master, I also include puzzles. One puzzle I came up with for one of my adventures was information hidden in a maze. I prepared this little video tutorial for you to also try it basically works like this the maze has a lot of dead ends and if you fill the paths that can be reached form the outside with color it will spell out or reveal information.
I also provide a handy template to be used along with the Free Software Inkscape if you’re interested.