Silicon Valley is geographically based too, and its center of gravity has shifted from Santa Clara County and the Valley proper, where the great first and second generation tech companies started, up through Palo Alto and Menlo Park in San Mateo County, and more recently, towards San Francisco proper.
Prior to the Season 3 finale your appearances were confined to flashbacks (on account of David being dead and all).   Brazil, with a population of almost 200 million is the most populated country in South America.
La Riconada in Peru is the highest habitation in the world at 16000ft from sea level. The highest city with a million plus population is El Alto, Bolivia which is 13000 ft from sea level. It also happens to be the 2nd most populous city in Bolivia after Santa Cruz. Views.