This impossible monument is a popular illusion. Can you work out the perspective of its columns?
Light and shadow is used to enhance the illusion. If you examine each of the columns you will see that their front sides merge with the background because of the shadows. Imagine them without shadows, but now try to work out the central foot!
This illusion was originally known as a ?Blivet?, and means an unidentifiable object where there are two different perspectives offered. The ?Blivet? first appeared on the 1965 cover of Mad Magazine and has been used as an illusion ever since.
Archive of illusions.org: