Major Cities of the World

San Francisco-United States

The City and County of San Francisco is the fourth most populous city in California and the fourteenth-most populous in the United States, with a 2006 estimated population of 744,041. It is located on the tip of the San Francisco Peninsula and is the focal point of the San Francisco Bay Area. San Francisco is the second most densely populated major city in the United States.
In 1776, the Spanish settled the tip of the San Francisco peninsula, establishing a fort at the Golden Gate and a mission named for Francis of Assisi. The California Gold Rush in 1848 propelled the city into a period of rapid growth. After being devastated by the 1906 earthquake and fire, San Francisco was quickly rebuilt.
San Francisco is renowned for its chilly summer fog, steep rolling hills, an eclectic mix of Victorian and modern architecture, and its peninsular location surrounded on three sides by the Pacific Ocean and San Francisco Bay. Famous landmarks include the Golden Gate Bridge, Alcatraz Island, the cable cars, Coit Tower, and Chinatown.
Geography
San Francisco is located on the west coast of the U.S. at the tip of the San Francisco Peninsula and includes significant stretches of the Pacific Ocean and San Francisco Bay within its boundaries. Several islands are part of the city, notably Alcatraz, Treasure Island, and the adjacent Yerba Buena Island. Also included are the uninhabited Farallon Islands, 27 miles (43 km) offshore in the Pacific Ocean. The land within the city limits roughly forms a seven by seven mile square (11 by 11 km), which has become a colloquialism referring to the city's shape.
The San Francisco Peninsula: San Francisco and, below it, northern San Mateo CountySan Francisco is famous for its hills. There are more than 50 hills within city limits.
Some neighborhoods are named after the hill on which they are situated, including Nob Hill, Pacific Heights, Russian Hill, Potrero Hill, and Telegraph Hill.
Near the geographic center of the city, southwest of the downtown area, are a series of less densely populated hills. Dominating this area is Mount Sutro, the site of Sutro Tower, a large red and white radio and television transmission tower. Nearby is Twin Peaks, a pair of hills resting at one of the city's highest points and a popular overlook spot for tour groups. San Francisco's tallest hill, Mount Davidson, is 925 feet (282 m) high, and is capped with a 103 feet (31.4 m) tall cross built in 1934.
The San Andreas and Hayward Faults are responsible for much earthquake activity, even though neither passes through the city itself. It was the San Andreas Fault which slipped and caused the earthquakes in 1906 and 1989. Minor earthquakes occur on a regular basis. The threat of major earthquakes plays a large role in the city's infrastructure development. New buildings must meet high structural standards, and older buildings and bridges must be retrofitted to comply with new building codes.
San Francisco's shoreline has grown beyond its natural limits. Entire neighborhoods such as the Marina and Hunters Point, as well as large sections of the Embarcadero sit on areas of landfill. Treasure Island was constructed from material dredged from the bay as well as material resulting from tunneling through Yerba Buena Island during the construction of the Bay Bridge. Such land tends to be unstable during earthquakes; the resultant liquefaction causes extensive damage to property built upon it, as was evidenced in the Marina district during the 1989 Loma Prieta Earthquake.


Beaches and parks
Ocean Beach runs along the Pacific Ocean shoreline, but is not suitable for swimming because the waters off the coast are cold and have deadly rip currents. Baker Beach occupies a picturesque setting just west of the Golden Gate Bridge and is where one of the few existing colonies of Hesperolinon congestum, the threatened Marin Dwarf Flax, can be found. The biggest and most well-known park is Golden Gate Park, stretching from the center of the city to the Pacific Ocean. Once covered only in grass and sand dunes, the park is planted with thousands of non-native trees and plants and is rich with attractions including the Conservatory of Flowers, the Japanese Tea Garden, and Strybing Arboretum. The Presidio, a former military base, and its Crissy Field section, restored to its natural salt marsh condition, are part of the Golden Gate National Recreation Area, which includes Alcatraz, and other regional parks. Buena Vista Park is the city's oldest, established in 1867. Lake Merced is a fresh-water lake surrounded by parkland.