San Diego is the eighth-largest city in the United States and second-largest in California, located approximately 120 miles south of Los Angeles and immediately adjacent to the border with Mexico. The city is known for its mild year-round climate, natural deep-water harbor, extensive beaches, long association with the United States Navy, and recent emergence as a healthcare and biotechnology development center.

The city is the seat of San Diego County and is the economic center of the region as well as the San Diego–Tijuana metropolitan area. San Diego's main economic engines are military and defense-related activities, tourism, international trade, and manufacturing. The presence of the University of California, San Diego (UCSD), with the affiliated UCSD Medical Center, has helped make the area a center of research in biotechnology.

San Diego has one of the top-ten best climates according to the Farmers' Almanac and has one of the two best summer climates in America as scored by The Weather Channel. San Diego's climate is characterized by warm, dry summers and mild winters, with most of the annual precipitation falling between December and March. The city has a mild climate year-round, with an average of 201 days above 70 °F and low rainfall (9-13 inches annually).

Many popular museums, such as the San Diego Museum of Art, the San Diego Natural History Museum, the San Diego Museum of Man, the Museum of Photographic Arts, and the San Diego Air & Space Museum, are located in Balboa Park, which is also the location of the San Diego Zoo. The Museum of Contemporary Art San Diego (MCASD) is located in La Jolla and has a branch located at the Santa Fe Depot downtown. The downtown branch consists of two buildings on two opposite streets. The Columbia district downtown is home to historic ship exhibits belonging to the San Diego Maritime Museum, headlined by the Star of India, as well as the unrelated San Diego Aircraft Carrier Museum featuring the USS Midway aircraft carrier.