Middle Grade adventure book about a child who finds a map in the spine of a book.

[Michelle]

I’m looking for a book that is a green hardback book. It is about a child who finds a map hidden inside the spine of a book. They have been told never to pull books off the shelves by their spines. However when the child does, the map falls out and the adventure begins. Probably dated from late 1950s to late 1970s.

[Capn]

Hi Michelle,

What sort of adventure takes place? Is this realistic fiction (i.e. a map of their town), or fantasy (dragons, magic, parallel dimensions, etc.)?

Can you remember what the map shows or anything on it?

Any other scenes or details you can give, however disjointed or incomplete or fuzzy? :)