Summarize this article in one sentence.
Google's headquarters is located at  1600 Amphitheater Parkway in the city of Mountain View, California. If you are driving from San Francisco, take the US-101 South to the Rengstorff Avenue exit. Continue to Amphitheatre Parkway.  If you are coming from another direction, take whatever other roadway and exit that will bring you to Amphitheatre parkway. Use Google maps to plot out your journey efficiently. Take either the number 32 or number 40 Mountainview city buses to the Googleplex. Both buses have stops close to the San Antonio Caltrain station, allowing you to get to Google's headquarters from San Francisco, San Jose, or South Bay.  To save money and time, opt to buy day passes for either transportation system. Mountainview city buses are operated by the Santa Clara Valley Transportation Authority. Caltrain is a commuter rail service that operates within the San Francisco Bay Area region. A day pass for the Santa Clara Valley Transportation Authority costs $7.00 while a one way ticket costs $2.25. A day pass for the Caltrain costs $7.50 while a one way ticket costs $3.75. There are 5 large parking lots for the Googleplex located at the top of the campus. Access these lots by driving north down North Shoreline Boulevard, just past Amphitheatre Parkway. Park for free in one of these lots and begin your tour! The parking lots are labelled A, B, C, D, and E. After parking, you will have to walk 5-10 minutes to access the Google campus. Walk down Bill Graham Parkway, located just west of the parking lots, until you reach Amphitheatre Parkway. Safely cross this street to access the main hub of the Googleplex.

Summary:
Drive to the Googleplex in Mountainview, California. Access Google's headquarters by train and bus if you are not driving. Park in one of the lots on the north end of the campus. Follow Bill Graham Parkway and cross Amphitheatre Parkway.