Impossible Triangle

Impossible Circle

This is a so-called "impossible object."

This means that it's impossible to build it.

But drawing it is not impossible, as you see in the image.

All the bumps are identical.
The one in the lower right corner is upside-down,

the image to the right is rotating.

Perpetually ascending staircase—how can the man go up all the time and come back to the same place over and over?

Trying to figure this out can give you a headache!

The red squares are the same color

in the upper part and in the lower part of the "X"

The diagonal lines are parallel.

There are no gray spots at the corners of the squares.

 Parallel lines at sunrise

  The center circles are both the same size.

The vertical lines are both the same length.

Three-Prong Fork

  Ambiguous Cubes

  There are only white circles at the intersections.

There are no black dots.

  Wavy Squares? No! 
The background of concentric circles makes the squares appear distorted.

Warped Square? 
There are no curved lines in this figure.

The rows of black and white squares are all parallel.

None of them slope.

Are the vertical blocks parallel or straight?

Rotating Wheels 
The circles appear to rotate when you move your head closer and further away from the screen while looking at the dot in the center.