Atlas Obscura, perhaps in the same vein as our post about unusual little-known literature, offers a look at an even stranger collection of books. These books are housed at Padua University and are made entirely from wood:
What is particularly curious about these books is that while most books
are made of wood, pulped into paper, these books are both about trees
and constructed of them; their construction and contents are truly one
and the same. Each volume is about a different species of tree, with
its cover made from the wood of that tree, showing both wood radial,
longitudinal, and cross profiles. And on each spine is a section of the
tree’s bark.
You can see more here.