For the solution to the Mystery Hole Brain Teaser, click here.
If you like these optical illusions, you'll enjoy these Mind-Bending Optical Illusion Books
If you like these optical illusions, you'll enjoy these Mind-Bending Optical Illusion Books
Watizzits? - Views-to-ConfuseProblem Postage - Spot the Difference PuzzlesAmbigrams - Topsy-Turvy Matchbox Art
Optical Illusions - The Missing PrincessSpot the Difference PuzzlesOptical Illusions - Checker Shadow Illusion