I find it inexplicable that M. C. Escher joins DOP so late. It just seems impossible to do him justice by using words to describe his ingenious creations. There is so much more in it than meets the eye. His work is the perfect coming together of mathematics and art. He explored complex mathematical ideas, purely driven by an intuitive visual understanding and without any scientific background. What he reveals is a world that is far away from our general perception of reality, a world of mathematics, a world of abstractions, anticipating deep features of modern day cosmology.
Here’s a short BBC documentary from 2015:
The Art of the Impossible: M. C. Escher and Me
Another artist on DOP that fits the theme: Oscar Reutersvärd