You should never leave the lock box for the keys unlocked. Oddly enough there was nothing in the room that would have been locked and needed these keys. I’m assuming what ever it was has been taken in the years since the school was closed down.
More evidence that the city has done a good job keeping this school locked down despite all the broken windows above the first floor. I was impressed that not only was the last lesson still on the chalkboard, but that the teacher had the foresight to mark the board with “save” so the custodial staff didn’t wash it. I was also quite impressed that so few people added their commentary to it.
Always cover your microscope. For that matter, make sure you leave the eye piece attached. Like most things in this school this microscope is salvageable, although it would probably be cheaper to buy a new one than clean this one and get a new eye piece.