I like stereograms. It is like chocolate eggs with a toy inside. You never know what toy it is until you eat the egg and put the toys part together.
Looking at a stereogram first thing you see is something like random pattern. If you look at it properly you can see a surprise.
Today I found

and his great work. But one of them as really stunning and awesome.
Ladies and Gentlemen, The Chessboard:

.
Yes, it _is_ a stereogram. Really.
Unbelievable, isn't it?