The Silicon Valley lies in the South Bay of the San Francisco Bay. Once best known for its prune orchards, the area underwent explosive growth with the creation of the high-tech industry in the 1960s. Although much of the area suffers from the suburban sprawl typical of much of the western United States, it still has some remarkable charm. The nearby Santa Cruz mountains make for a welcome respite from bustling 21st-century cyberliving.
The term Silicon Valley was invented in the mid 1970s. Naturally, the local residents had names for their region prior to this newfangled name, such as "Santa Clara Valley" and "Valley of Heart's Delight," and still use them. The term Silicon Valley overlaps several of the pre-existing names for this region including parts of the South Bay and Peninsula.
Because the electronics industry is considered somewhat prestigious, nearby communities often redefine the term Silicon Valley to include themselves. Some of these communities were mostly farmland when the term was invented, so it was pretty natural that the term didn't originally include them, but they might reasonably be considered part of the Silicon Valley now. On the other hand, the Mercury News's Silicon Valley 100 Index extends the term to such fabulous lengths that even Watsonville — a small coastal community on the other side of the Santa Cruz mountains — is included.
So if you're looking to visit the Silicon Valley as a tourist, look to Palo Alto, Santa Clara, and the museums of San Jose. But if you're visiting a company which is "in the Silicon Valley," you may have to look farther afield around the South Bay, Peninsula, and East Bay regions.
Birthplace of Silicon Valley
Designated by the State of California as a historical landmark, the "HP Garage" located at 367 Addison Avenue, Palo Alto, is the birthplace of the world's first high-technology region, "Silicon Valley."
As inscribed on the monument, "the idea for such a region originated with Dr. Frederick Terman, a Stanford University professor who encouraged his students to start up their own electronics companies in the area instead of joining established firms in the East. The first two students to follow his advice were William R. Hewlett and David Packard, who in 1938 began developing their first product, an audio oscillator, in this garage."
The HP Garage was designated California Historical Landmark No. 976 in 1989.
Stanford Research Park
In the 1950s, Professor Frederick Terman suggested to Stanford University that the newly founded Stanford Industrial Park leases be limited to high-tech companies so a center of high technology could be created.
In October 1951, Varian Associates signed a lease with the University for a 10-acre tract along El Camino Real and built their $1 million R&D laboratory in the Stanford Industrial Park the following year. Soon after, Eastman Kodak, General Electric, Preformed Line Products, Admiral Corporation, Beckman Instruments, Lockheed, Hewlett-Packard, and others followed suit.
Stanford Industrial Park was renamed Stanford Research Park in 1974.
By 2005, Stanford Research Park was home to more than 150 companies in electronics, software, biotechnology, as well a number of top law firms, financial service firms, consultancies, and venture capital companies. R&D and service companies occupied some 10 million square feet in more than 160 buildings on 704 acres.
Stanford Research Park is considered by many the foundation of Silicon Valley.
Origin of the Name
"Silicon Valley", first used by Don C. Hoefler, publisher of Microelectronics News, in his article titled "Silicon Valley USA" on January 11, 1971, has become synonymous with center of high technology research and development. "Silicon" refers to the high concentration of semiconductor and computer-related industries in the area at the time. "Valley" refers to the Santa Clara Valley.
Silicon Valley today has extended beyond the greater Santa Clara Valley which includes the entire Santa Clara county and parts of San Mateo, Alameda, and Santa Cruz counties in northern California. It is the southern portion of the San Francisco Bay Area, also known as, South Bay, which covers cities such as San Jose, Santa Clara, Sunnyvale, Cupertino and Los Gatos. Silicon Valley also includes parts of the San Francisco Peninsula from Redwood Shores down to the South Bay, and cities such as Fremont and Newark in the lower East Bay.
San Jose Airport connects to Light rail by bus line whose website is http://www.vta.org/. Taxis also serve the airport and can transport you to Sunnyvale for around $25 one way, for example. San Jose Airport connects to Caltrain and a bus line 22 by bus line ???.
Be careful to check for ticks  after hiking in fields in the bay area. There is a high rate of lyme disease transmission in the Bay Area. If a bulls' eye rash develops at the tick bite site, immediately seek medical help and treatment with antibiotics.