The Financial District is where most "traditional" nine-to-fivers work. This includes businesses like banks, law firms, advertising companies and more. It's got tall buildings, expensive lunch restaurants, and Starbucks, Starbucks, Starbucks. The Embarcadero and Montgomery BART stations are where these worker bees pass through when they're headed for another long day at the office.... If you're looking for it, it's south of North Beach and east of Chinatown. Once you hit Market, you've gone too far.
It's the area near the last three stops on the BART system. Just look up and look for offices.
Sometimes called "FiDi," which may or may not be a totally gross word.