The city of LA is launching a competition to design a new streetlight. LA's chief design officer Christopher Hawthorne tells DnA about the history of LA's streetlights, and what the city is looking for in a new streetlight.

And when the Berlin Wall came down in 1989, there were only 30 walls separating nation states around the world. Now there are over 77 -- and most of those have gone up in this century. A show at the Annenberg Space for Photography explores why walls are a global phenomenon.