Impossible Objects really get us chasing our tail. Our brain tries to do its best usually, however, there are instances when it fails to process correctly what the eye sees.
The brain makes sense of shapes and symbols. It's trying to put them together like a jigsaw puzzle, formulating that which isn't there to that which is believable. 2D figure is subconscionsly interpreted as 3D object although such object can not exist.
The Penrose Triangle
This impossible tribar is one of the most well-known Impossible Figures. Try to trace a line in the triangle and you would have to trace it three times around the triangle before coming back to where you started. (by Roger Penrose)
The Penrose Stairs
This is a variation on the Penrose Triangle. You could climb the stairs forever and never get any higher. That is only possible in two dimensions. This impossible staircase can be found in the paintings of M. C. Escher and also in the movie Inception by Christopher Nolan. (by Roger Penrose)
Dice
Try to arrange dice like this. There are many more variations on the Penrose Triangle, however, this one is simply great.
Devil's Fork
This impossible object (blivet) is called also "Three-Pronged Poiuyt" or "Schuster's Conundrum" (by D. H. Schuster)
Dancing Elephant
This is one of classic optical illusions. Try to count the number of his legs (by Roger Shepard).
Impossible Object
Another impossible figure.
Impossible Cube
A realistic photo or just another undecidable figure?
Impossible Building
Could you build this?
Impossible Arch
Great impossible arch (by Roger Shepard).
If you like these brain teasers then feel free to share them with your friends.