Silicon valley is the Valley of Hearts Delight. Silicon Valley is the home to 40 cities in the south San Francisco Bay Area that crosses four countries such as, from San Mateo to Gilroy, Fremont to Scott's Valley. Silicon Valley is the 10th largest city which includes San Jose and cities small and large in Santa Cruz, San Mateo, and Santa Clara.
http://www.siliconvalleyonline.org/where Silicon Valley got it's name because it originally cited to the regions large silicon chip.innovators produce, but eventually became the high tech businesses in that area. Silicon Valley is to be the leading high tech hub because of its large amount of engineers.
http://askville.amazon.com/Silicon-Valley-officially-famous/AnswerViewer.do?requestId=12725697
Silicon Valley is important because its home of the big technology buildings, its also important because of the high-tech organizations.