That is a kinda boring link, but here's a high-quality (and dramatic!) exposition I encountered recently about Escher's correspondence with Coxeter and the meth

That is a kinda boring link, but here's a high-quality (and dramatic!) exposition I encountered recently about Escher's correspondence with Coxeter and the method by which one might construct figures like his Circle Limits without a computer. If you're further intrigued, there are more related links at the bottom. http://www.ams.org/samplings/feature-column/fcarc-circle-limit http://www.ams.org/samplings/feature-column/fcarc-circle-lim...