The main goal of the thesis is to emphasise the importance of mythification and the representation of Celtic mytholgy through an analysis of two books by the English author Alan Garner. The first examined book, Elidor contains a large number of Celtic inspirations. its main characteristic is the introduction to its new world can be seen as the portrayal of the Celtic Otherworld. The other researched book, The Owl Service touches upon the Legend of Blodeuwedd, one of the legends of the Mabinogion. In addition, both novels play an important role in teaching children about culture, conflicts and human behaviour.