Grand Library Route Map
There is a mark on the top left of the map. This could be where the puzzle is.
Details 
Category: Quest Item
Rarity: 3
Background Description
A small scroll inside the Sundial, mapping the possible routes of the "Grand Library", the central database in City Hall. There is a red circle on the top left corner of the map that possibily indicates the location of a secret contraption, indicating a confusing detour to the destination.
Grand Library Route Map
Top left corner of the map carries a highlight mark. This may indicate the location of the puzzle.