Codex Seraphinianus, originally published in 1981, is an illustrated encyclopedia of an imaginary world, created by the Italian artist, architect and industrial designer Luigi Serafini  over a period of thirty months, from 1976 to 1978. The book is approximately 360 pages long (depending on edition), and written in a strange, generally unintelligible alphabet.
Originally published in Italy, the book has since been released in a number of different countries.
The word "Codex" in the title means "book" (from Latin caudex), and "Seraphinianus" is derived from the author's last name, Serafini. (In Italian, serafini refers to the seraphs.)
October 2013 A new edition of the Codex issued .
More information on the Wikipedia page .
There are a number of websites and videos on the book.