Access to Elevators at Building 3

[Green route] Enter the Building 3 from the entrance facing the Building 2 (Aizu Museum). Upon entering the building, turn right immediately. Around the corner, there are three elevators.
If you do not turn right immediately and pass through automatic sliding glass doors, you see the escalator coming from the 2nd floor. If that is the case, you go too far.
[Blue route] You can also use the entrance with the door nob that is facing the Building 1.
Just in case you cannot find the elevator hall, please visit the security guards room indicated by the yellow arrow above.