The City and County of San Francisco is the fourth most populous city in California and the 14th most populous city in the United States. The city is located at the tip of the San Francisco Peninsula, with the Pacific Ocean to the west, San Francisco Bay to the east, and the Golden Gate to the north.
Among the most densely populated cities in the country, San Francisco is part of the San Francisco Bay Area metropolitan area. It has a population over 800,000, but is the center of a metropolitan area of millions.
San Francisco is just one of the cities which makes-up the entire San Francisco Bay Area. San Francisco's neighbours, cities and towns to the east of the Bay Bridge, north of the Golden Gate Bridge, and south of it are all in separate counties, each with their own city government and local public transportation systems.
With over 35 international financial institutions, 600 companies, and a large support infrastructure of professional services including law, public relations, architecture and design also with significant presence in the city, San Francisco is designated as one of the ten Beta World Cities. San Francisco has been positioning itself as a biotechnology and biomedical hub and research center.
Tourism is the backbone of the San Francisco economy. Its frequent portrayal in music, film, and popular culture has made the city and its landmarks recognizable worldwide. San Francisco attracts the fourth-highest number of foreign tourists of any city in the U.S.
San Francisco is famous for its landmarks, including the Golden Gate Bridge, Alcatraz Island, the cable cars, Coit Tower, and Chinatown, its steep rolling hills, and its eclectic mix of Victorian and modern architecture.
San Francisco is famous for its hills. There are more than 50 hills within city limits. Some neighbourhoods are named after the hill on which they are situated, including Nob Hill, Pacific Heights, Russian Hill, Potrero Hill, etc.
San Francisco's sharp topography has created a series of microclimates. For instance, there is more fog on the western side of the city, closer to the ocean. There can also be large variances in rainfall between different parts of the city thanks to the tall hills in the center of the peninsula.
San Francisco's climate is characteristic of California’s Mediterranean climate with mild, wet winters and dry summers. San Francisco's climate is strongly influenced by the cool currents of the Pacific Ocean which tends to moderate temperature swings and produce a remarkably mild climate with little seasonal temperature variation.
Average summertime high temperatures in San Francisco peak at 21 °C and are 9 °C lower than in nearby inland locations like Livermore. Winters are mild, with daytime highs near 15 °C. May through September is very dry, but rain is common from November through March. Snowfall is extraordinarily rare.
San Francisco is a major city in California, the centrepiece of the Bay Area, well-known for its liberal community, hilly terrain, Victorian architecture, scenic beauty, summer fog, and extreme ethnic and cultural diversity. These are only a few of the aspects of the city that make San Francisco one of the most visited cities in the world.