A mystery solved! I know the secred behind the door.

I have solved a mystery in the last few days.  There is a place whre I go with closed doors.  I always wondered what was behind those doors.  Now, I know.  There is a short and large corridor behind the doors.  Further, there is a perpendicular corridor, more narrow but long.  So, the door is connecting two corridors by a large and short corridor.  I had the presence of mind to take photos.
Here is the doors:

The above photo is behind the doors.  It seems to be the reverse of the side where I am.  It is fun to know about this.  At the smae time, it remove the mystery.