Of the millions of people who visit San Francisco each year, 87 percent of them go to Fisherman's Wharf. Waterfront marketplaces include The Cannery, The Anchorage, Ghiradelli Square, and Pier 39. The Wharf's working hub is called Fish Alley and it annually sells thousands of tons of sole, shrimp, salmon, sea bass, squid, and other deep-sea delicacies. Between mid-November and late June, the crab season, people line up for the best of the catch. Here's an idea for an impromptu picnic: fresh crab and a loaf of sourdough bread from a nearby bakery.