The Codex Seraphinianus — a mysterious book by an artist named Luigi Serafini, which is often described as seeming to be “a visual encyclopedia of an unknown planet” — has been placed online in its entirety.
Back in 2007, Justin Taylor wrote about the book in the Believer, and in 2009 he wrote a follow-up article about reader response to it over at HTMLGIANT. You may want to save these links for the weekend; it’s worth spending half a day or more with this amazing book and the stuff Justin has written about it.