Photo by J Scott Shannon.
Lining the 4th floor corridors are framed enlargements of some of the most extraordinary images of old Los Angeles I've ever seen. I wish my old digital camera had image stabilization, or I'd be posting about 50 of the pics here! A handful I've seen before in the USC/LAPL archives, but the vast majority of the photos were totally new to me.
If you're an L.A. history nut like me, I'd really urge you to treat yourself to a visit to the 4th floor. I've been there a total of three times now (my first visit was last year), and I intend on going back every chance I get. Don't forget to go up to the observation deck on the 27th floor, too! It's open to the public during business hours on weekdays.