Downtown Mountain View and the Castro Street corridor are walkable from the Caltrain station. For the Computer History Museum, Shoreline Park, and the Googleplex campus, you'll need a bike or car — they're two to three kilometres north of downtown, easily reached via the dedicated Shoreline Boulevard bike path.
Bike rental and bikeshare options are available near the Caltrain station. The terrain is flat and the cycling infrastructure is better than most American cities its size. The VTA light rail system connects Mountain View to Sunnyvale and San Jose, though it runs infrequently. Rideshare is widely used. There is no direct rail connection to the East Bay BART system without going through San Jose or San Francisco first.