I love M.C. Escher, so I decided to make my own version based on his art. The main difference is that mine has 3 sides instead of four. Three sides print a lot easier and look just as good ;)
Enjoy.

I have included 2 STL files. One with supports and one without.
I recommend printing at 100% (10cms).
This print is not easy, it has supports for the outside and inside. To remove them you need a pair of thin pliers.
I printed at 0.15mm and it took 9 hours.