South Van Ness, pulsing with morning traffic, may not be the most charming of Mission streets. But the Inn San Francisco, set serenely above street level, occupies one of those glistening Italianate Victorian mansions that unexpectedly appear, like shining white ships under full sail, in this continually surprising city. Fred Girodat, co-manager, and Marty Neely, owner, are authorities on the area. A guest's innocent question about a good place to eat leads to a sit-down conference in the inn's breakfast room, complete with neighborhood maps, Magic Markers, heartfelt differences of opinion, lists of phone numbers, and a file stuffed with reviews.

The Beats had North Beach. Flower Power happened in Haight Ashbury. Generation X occupied the lower Haight - every generation discovers a new bohemia in San Francisco. The corner of 16th and Valencia in The Mission feels like ground zero for the new millennium.

The smoky fragrance of strong West Coast coffee floats along on a trace of morning fog. Valencia Street is reinventing itself at hyperspeed, but right now the most intriguing cafes, taquerias, secondhand bookshops, and street life happen around the 16th Street intersection, with another zone of activity a few blocks away, between 20th and 22nd. Sample street scene: a couple of skinhead surfer boys leaning on the fender of their battered old Buick ragtop reading homemade poetry to a young woman in a Lycra suit and serious running shoes, who listens while taking calls on a flip phone and looks like she could float an IPO before breakfast.

Things evolve, even in bohemia.

Until recently, The Mission was predominantly Latino, and 24th Street still retains this old Mission atmosphere. It's about as neighborhood as it gets in San Francisco, which has lately become one of the sleekest, most polished cities on the planet - at some cost in texture.