Darwin is hidden down a small side street, with just a small wooden sign marking the door. The easiest way to find it is to look for the huge line spilling out the door during lunch hours. It is an unexpected home for arguably San Francisco's best sandwiches and salads.
Thick hot sandwiches, cold sandwiches, salads, baguettes smothered with cheese, seasonal fruits and greens -- you really can't go wrong with anything you get here. The menu changes regularly depending on the season.
People rave about the kale salad. I'm more of a sandwich girl; the roast beef and shrimp sandwiches are a sure bet.