Think of San Francisco’s largest Halloween pub crawl as trick-or-treating for adults. Thousands of costumed revelers take over Polk Street for drinks, music and dancing, and costume contests. This year, whether you show up on foot or via the San Francisco Party Bus, you’re sure to be in spooktacular company at 20 haunted watering holes including Mayes, Nick's Crispy Tacos, Del Mar, and Wonder SF. It’s free to join the festivities.