It is very true that maps are not always the reality.
Sometimes they are not even close.
(and I kind of miss the clouded areas with the "Here There Be Monsters." caption that used to appear on really old charts)

Tourist maps for small parks are about the worst to work with and sometimes it is worth drawing your own instead. It seems a lot of them were drawn on the backs of napkins by the student help after a hard night of partying and based on vague sketch the park maintenance foreman made for the students.
The ones that are actually to scale were likely from the landscaper's plans and represent the installation as planned instead of the installation as built.
Then there is the question of when the map was drawn and what has changed since then.

So yeah, never totally trust any map.