San Francisco occupies the northern tip of a peninsula between the Pacific Ocean and San Francisco Bay, bordered by Daly City to the south and connected to Marin County via the Golden Gate Bridge. The city's neighborhoods—from the Marina and Pacific Heights through the Mission, SOMA, and the Sunset—form distinct districts shaped by the city's 43 hills and microclimates. The economy centers on technology, finance, and tourism, with major employers in biotech and healthcare concentrated around UCSF's Parnassus and Mission Bay campuses, while the Port of San Francisco and SFO airport anchor transportation and logistics throughout the Bay Area.