Don’t blink or you’ll miss the next “new” San Francisco. This is a city that’s reinventing itself with every refresh of your Twitter feed, with cranes rising all over downtown and an army of young tech workers pouring into neighborhoods across the city. In the ’60s, San Francisco was synonymous with the hippie counterculture; in the ’90s, it was the dot-com boom (and eventual bust, in the early 2000s); more recently, it was the ripening of the Bay Area food movement. Now it’s home to such new-establishment icons of the digital economy as Airbnb, Uber and, yes, Twitter. But don’t be fooled by the shiny patina: San Francisco is more than just the physical headquarters of our virtual world. There are some things that haven’t changed, and by themselves, are reason enough to revisit: the mind-boggling views along that glorious waterfront; the Mission’s still-feisty, freaky, welcome-all-comers character; the meandering natural pleasures of Golden Gate Park. Even when classic San Francisco rubs up against new San Francisco, the friction, though at times contentious (Google bus protests, the anti-eviction fight), is also where the community-conscious activist roots of this city are as vital and visible as ever.