The Voynich Manuscript is an illustrated book of unknown authorship written in a unique script and language, neither of which has yet been deciphered. On almost every page, the text is accompanied by very unusual hand-drawn illustrations ranging from botanical specimens of plants not found on earth to elaborate cosmological diagrams.

The Codex Seraphinianus is an exhaustively illustrated encyclopedia pertaining to an imaginary universe, created by the Italian artist and designer Luigi Serafini. It is written in a unique script, and its underlying language (if any) has not yet been deciphered. It may have been inspired in part by the Voynich Manuscript.