The Mabinogion is a medieval Welsh story cycle, drawn from a pair of manuscripts, its 11 tales mixing Arthurian myths, pre-Christian (perhaps even Iron Age) stories, folktales and other legends. Seren Books, a small Welsh publisher, has launched a series called 'New Stories from the Mabinogion', in which contemporary Welsh writers create new versions of these myths.
The four books in the series so far (I'm not sure if more are planned) all have lovely matching covers of cut paper, each featuring what I guess to be the meat-eating tree discovered by Gwydionin in the Blodeuwedd tale (modernised in a science-fiction version by Gwyneth Lewis). I'm very much a fan of the making and photographing of things like this, when it would be so easy to just create them in Illustrator or Photoshop.
I find that I actually already have two different versions of the Mabinogion in my library: the original English translation by Lady Charlotte Guest, illustrated by well-known fantasy artist Alan Lee, as well as a freeish series of novelisations by Evangeline Walton (with a cover also by Alan Lee).