See san franciscos most famous sights aboard a double decker big bus that loops around the city this 24 hour pass makes it easy for you to check out union square the palace of fine arts and pier 39 among other big name attractions at your own pace simply hop on and off the bus at nearly 20 designated stops want more big bus includes walking tours of chinatown north beach and barbary coast three of the citys most popular areas upgrade to a 48 hour bus pass to also include a panoramic