This photograph features San Jose, Santa Clara, Sunnyvale, Mountain View, Palo Alto, and Menlo Park—the heart of world-famous Silicon Valley. The southern end of San Francisco Bay is flanked by the Diablo Range to the east and the Santa Cruz Mountains to the west. The linear runways of San Jose Municipal Airport and Moffett Field Naval Air Station are barely visible near the southern end of the bay. The surrounding marshlands have been diked for salt harvesting. The vivid colors result from different species of algae and different salinity levels in the large salt ponds.