Codex Seraphinianus is an experience. It's the picture book that the inner-child of your imagination has been dreaming of. It is, in essence (if you can even adequately capture the essence of this book), an encyclopedia of a fantastic  and imaginary world, a world where trees uproot themselves and swim away in vast numbers, where deer heads are grown in plant pots, where grass grows out of the palms of men's hands. It's where your wildest dreams, nightmares and/or hallucinations have gone to die. And if all the psychotic imagery wasn't difficult enough to get your head around, it isn't even written in a real language. In fact, it's written in a language that has yet to be deciphered by anybody; it's generally accepted that the language of Codex Seraphinianus is entirely meaningless, and will never be understood. 

If you are already familiar with The Voynich Manuscript, the Codex Seraphinianus may seem like nothing more than a desperate attempt at becoming "the world's second most mysterious manuscript", but it is certainly worth your attention nonetheless. The script, though not as beautiful in my opinion as that of the Voynich Manuscript, has a fascinating design that will enthrall linguists and conlangers alike. The Codex Seraphinianus is inspiring, absurd, beautiful, mysterious and grotesque. 

If you like fantasy and surrealism, this book will leave your brain tingling, like the first surreal cartoon you ever witnessed as a child (Stoppit and Tidyup, anyone?) . I guarantee that your dreams will be plagued by walking Easter eggs and men with evergreen forests growing out of their heads for months to come. 

This book will serve as a fountain of inspiration for the poor souls suffering from writer's/musician's/illustrator's/anything's block. Whether or not this is "your sort of thing" you would be almost madder than the book itself not to 'read' it. 

I have recommended this book to so many people, and I will continue to recommend it. There is so much more that I could say about this book, but it really is simply one that you have to read yourself. It is, unfortunately, ridiculously expensive, but like all things you will be able to find a sneaky pdf version of it online somewhere. It is an absolute treasure and it has stayed with me from the day I first saw its cover image - a couple who slowly transform into a crocodile (slightly NSFW, maybe): 

The graphemes for <w> are a little hard to decipher. They look a bit like Cyrillic <ϭ> or Greek <σ>. I know that in Mediæval Welsh texts, a letter that looked similar to the number <6> was used for this letter, so it's likely based on that (I don't think it's available in Unicode yet). Since neither of these however will combine with a circumflex, I'm going to be boring and just use the <ϭ> for both <w> and <ŵ>.

In all fairness, it is a complete mess of an orthography. But it has its charms, and the fact that you can tell which letters are mutations is useful. Apart from that though, it's an awful, awful mess. Just for fun here's a little comparison of the first verse of the Welsh national anthem in both orthographies: 

Contemporary Welsh: 
Mae hen wlad fy nhadau yn annwyl i mi,
Gwlad beirdd a chantorion, enwogion o fri;
Ei gwrol ryfelwyr, gwladgarwyr tra mad,
Dros ryddid collasant eu gwaed.

This silly Welsh: 
Mae hen ϭlad vᶌ t̔adau ᶌn annϭyl i mi, 
Gϭlad beird̓ a ćantorion, enϭogion o b̓ri; 
Ei gϭrol rᶌvelϭyr, gϭladc̓arϭyr tra mad,
Dros rᶌd̓id col̔asant eu gϭaed. 

Despite being messy, I think it's fairly cool-looking. I'm personally a big fan of having lots and lots of diacritics (Vietnamese, hnngg). Being the big orthography geek that I am, I might spend lots of time learning to read and write this fluently. Maybe it would make a useful shorthand for Welsh? Or maybe it should just stay in that book forever where it belongs.