Mount Vaca.

Something worth seeing between San Francisco and Sacramento--the view from Mount Vaca. Nearly the entire northern Sierra Nevada is visible from up here--from Mt Lassen to Yosemite. Plus Cache Creek, the Napa area, Mt Tamalpais, much of the Bay Area, Mt Diablo, the delta and the majority of the Central Valley. A great, great view, especially if you know what you're looking at.