All novels should start with maps and floor plans

Fed by Birds is reading old detective novels and particularly enjoying the maps and diagrams that always accompany the text. Why imagine the space in the novel when the author can lay it out for you? (I personally just like that I can flip back to the front of the book whenever I need that visual reminder).

I don't have much to add besides a strong endorsement - if your book deals with space, why not consider mapping it out for us?