The first impression of San francisco was more about Silicon Valley culture since I was attending to the Evernote conference in 2013,and I had a crush on this city immediately without going through every hot spot here.
Up and down hills, seashore and piers,those windy and foggy days, also, the diversity of cultures here are the best combination of a perfect city.
To me, San francisco is the intersection of humanity and technology

iPhone 6s/ VSCO Cam/ Instagram 

BGBG

SFO | Pier | Polk St. | SFMOMA | Bay Bridge | City Hall | Market St. | AT&T Park | The Cathedral of Saint Mary of the Assumption | Lombard St. | Union Square | TransAmerica | Fairy Land | China Town | Golden Gate Bridge | Yerba Buena