Adomnán wrote a geographical work. How did he view the world around which he imagined people travelling. This raises questions about the state of contemporary geographical knowledge and whether we can assume that he shares our notions of time and space. In fact, both are different. Here mental maps are used to allow him to tell us about his world rather than about the past of ours. We can use a series to reconstruct this world: (i) a T–O map to explain the actual sequence of movement in De locis sanctis and why Arculf’s arrival in Iona did not raise any questions for him; (ii) a Square–V map of the races of mankind; (iii) a map of circles based on Luke and Acts to explain the division of De locis sanctis into books; (iv) a map of scriptural signs which would explain the temporal inconsistencies in the description of places; and (v) an eschatological map which shows the book beginning at the gates of heaven and ending at the gates of hell.