Player cannot close this corner over here, and "guests" are stuck here searching for a path (they seem to like going through map border a lot).And may staff also go a long way all the way around the museum to get to the other side to enter the building to do maintenance.

Many take a path like this instead of going through the building:

The long path quickly deteriorates guest happiness, and my solution is to kick them out if they go the wrong path, using the "reveal thief" button. The museum is at 300+ guests already, so anyone kicked out will be replaced soon enough.

But this is still quite frustrating.

Please allow building in the two blocks that is leaking guests to the outer rim... Or at least allow placing a hedge...