San Francisco Bay is a shallow estuary in the U.S. state of California. It is surrounded by a contiguous region known as the San Francisco Bay Area (often simply "the Bay Area"), dominated by the large cities San Francisco, Oakland, and San Jose. San Francisco Bay drains water from approximately 40 percent of California. Water from the Sacramento and San Joaquin rivers, and from the Sierra Nevada mountains, flow into Suisun Bay, which then travels through the Carquinez Strait to meet with the Napa River at the entrance to San Pablo Bay, which connects at its south end to San Francisco Bay. It then connects to the Pacific Ocean via the Golden Gate strait. However, this entire group of interconnected bays is often called the San Francisco Bay. The first European to see San Francisco Bay is likely N. de Morena who was left at New Albion at Drakes Bay in Marin County, California by Sir Francis Drake in 1579 and then walked to Mexico. The first recorded European discovery of San Francisco Bay was on November 4, 1769 when Spanish explorer Gaspar de Portolà, unable to find the port of Monterey, California, continued north close to what is now Pacifica and reached the summit of the 1,200-foot-high (370 m) Sweeney Ridge, now marked as the place where he first sighted San Francisco Bay. Portolá and his party did not realize what they had discovered, thinking they had arrived at a large arm of what is now called Drakes Bay. At the time, Drakes Bay went by the name Bahia de San Francisco and thus both bodies of water became associated with the name. Eventually, the larger, more important body of water fully appropriated the name San Francisco Bay.