The Scarlet Rope by Norman Parker
This painting from British surrealist artist Norman Parker is a reworking of a familiar optical illusion. Glastonbury Tor, a holy hill in Southwest England, can be seen in the background through the impossible columns / pillars. As you move from the top of the painting to the bottom, the four square columns transform into six round pillars.
Despite having no formal art training, Norman Parker has been painting on both an amateur and semi-professional basis for over 50 years.
(via Norman Parker)