Arcade Building: 540 S. Broadway

This beauty, also known as the Mercantile Arcade (original name), Broadway Arcade and Spring Street Arcade, dates back to the early 1920s. Who knew they had malls back then? Okay, so the upper floors were mostly office buildings, and the ground floor shops sported a lot of "practical" shops where you'd pick up stamps and office supplies. Still, it's lovely, and even beter, it's still here!
Visit this cool site for more details about the Arcade Building (and similar arcades).