This maze is decently sized, and right smack dab in the middle will be a room surrounded by glowstone. Inside the room will be expensive/rare items.
The maze itself will have little to no lighting at all, making it more difficult at night time.
If I am not mistaken, the passageways are too small for any mob to spawn, so for anyone that would like to have monsters spawn inside the maze, i would suggest zombie/skeleton spawners in all the of dead-ends.