San Francisco is the cultural, commercial, and financial center of Northern California and the only consolidated city-county in California. It is the fourth-most populous city in California, after Los Angeles, San Diego, and San Jose. A popular tourist destination, San Francisco is known for its cool summers, fog, steep rolling hills, eclectic mix of architecture, and landmarks, including the Golden Gate Bridge, cable cars, the former Alcatraz Federal Penitentiary, Fisherman’s Wharf, and its Chinatown district. San Francisco is also the headquarters of five major banking institutions and various other companies. San Francisco is a center of major activities in the USA.