Escher's “Ascending and Descending” in Lego

This is excellent! I love recreations of illusions such as this -- a friend of mine's PhD student once knitted a klein bottle of all things!!! Pic here: https://www.filepicker.io/api/file/dBRNg4lwQVKJ1r8ziQNi

There are also a lot of cool optical illusions you can recreate in your browser - e.g. https://www.overleaf.com/latex/examples/tagged/illusions

(I'm one of the founders of Overleaf, so any feedback much appreciated, thanks!)

This was my favourite of the Escher Legos. I seem to remember Andrew telling me the cowls only came in one Lego set. With one in each set...