Del Puerto Canyon, to be exact!
I occasionally drive up and over Mount Hamilton from San Jose to Patterson- just to see the scenery. The highway, California Route 130, makes its way down into the San Antonio Valley, then turns east down through Del Puerto Canyon.
Every time I make the trip I am amazed at how near this mountainous terrain is to the San Francisco bay area. Our local weather prognosticators talk often about the "micro climates" of the bay area, but the truth behind the buzzwords is obscured until the sights are seen in person.