San Diego County, California in the context of "USS Nimitz"

Southern California (commonly shortened to SoCal) is a geographic and cultural region that generally comprises the southern portion of the U.S. state of California. Its densely populated coastal region includes Greater Los Angeles (the second-most populous urban agglomeration in the United States) and San Diego County (the second-most populous county in California). The region generally contains ten of California's 58 counties: Los Angeles, San Diego, Orange, Riverside, San Bernardino, Kern, Ventura, Santa Barbara, San Luis Obispo, and Imperial counties.

Although geographically smaller than Northern California in land area, Southern California has a higher population, with 23.76 million residents as of the 2020 census. The sparsely populated desert region of California occupies a significant portion of the area: the Colorado Desert, along with the Colorado River, is located on Southern California's eastern border with Arizona, and the Mojave Desert shares a border with Nevada to the northeast. Southern California's southern border with Baja California is part of the Mexico–United States border.

The aircraft hijackers in the September 11 attacks were 19 men affiliated with al-Qaeda, a jihadist organization based in Afghanistan. They hailed from four countries; 15 of them were citizens of Saudi Arabia, two were from the United Arab Emirates, one was from Egypt, and one from Lebanon. To carry out the attacks, the hijackers were organized into four teams each led by a pilot-trained hijacker who would commandeer the flight with three or four "muscle hijackers" who were trained to help subdue the pilots, passengers, and crew. Each team was assigned to a different flight and given a unique target to crash their respective planes into. Mohamed Atta was the assigned ringleader over all four groups.

The first hijackers to arrive in the United States were Khalid al-Mihdhar and Nawaf al-Hazmi, who settled in San Diego County, California, in January 2000. They were followed by three hijacker-pilots, Hamburg cell members Mohamed Atta, Marwan al-Shehhi, and Ziad Jarrah in mid-2000 to undertake flight training at Huffman Aviation flight-training school in Venice, Florida. The fourth hijacker-pilot, Hani Hanjour, who was not a member of the Hamburg cell, arrived in San Diego in December 2000. The rest of the "muscle hijackers" arrived in early- and mid-2001.

The Hale Telescope is a 200-inch (5.1 m), f/3.3 reflecting telescope at the Palomar Observatory in San Diego County, California, US, named after astronomer George Ellery Hale. With funding from the Rockefeller Foundation in 1928, he orchestrated the planning, design, and construction of the observatory, but with the project ending up taking 20 years he did not live to see its commissioning. The Hale was groundbreaking for its time, with double the diameter of the second-largest telescope, and pioneered many new technologies in telescope mount design and in the design and fabrication of its large aluminum coated "honeycomb" low thermal expansion Pyrex mirror. It was completed in 1949 and is still in active use.

The Hale Telescope represented the technological limit in building large optical telescopes for over 30 years. It was the largest telescope in the world from its construction in 1949 until the Soviet BTA-6 was built in 1976, and the second largest until the construction of the Keck Observatory Keck 1 in Hawaii in 1993.

Baja California, officially the Free and Sovereign State of Baja California, is a state in Mexico. It is the northwesternmost of the 32 federal entities of Mexico. Before becoming a state in 1952, the area was known as the North Territory of Baja California (Territorio Norte de Baja California). It has an area of 70,113 km (27,071 sq mi) (3.57% of the land mass of Mexico) and comprises the northern half of the Baja California peninsula, north of the 28th parallel, plus oceanic Guadalupe Island. The mainland portion of the state is bordered on the west by the Pacific Ocean, on the east by Sonora and the northern Gulf of California, on the north by the United States and on the south by Baja California Sur.

The state has an estimated population of 3,769,020 as of 2020, significantly higher than the sparsely populated Baja California Sur to the south, and similar to San Diego County, California, to its north. Over 75% of the population lives in Mexicali (the state's capital city), Ensenada, or Tijuana (the state's largest city). Other important cities include San Felipe, Rosarito, and Tecate.

The Palomar Observatory is an astronomical research observatory in the Palomar Mountains of San Diego County, California, United States. It is owned and operated by the California Institute of Technology (Caltech). Research time at the observatory is granted to Caltech and its research partners, which include the Jet Propulsion Laboratory (JPL), Yale University, and the National Astronomical Observatories of China.

The observatory operates several telescopes, including the 200-inch (5.1 m) Hale Telescope, the 48-inch (1.2 m) Samuel Oschin telescope (dedicated to the Zwicky Transient Facility, ZTF), the Palomar 60-inch (1.5 m) Telescope, and the 30-centimetre (12-inch) Gattini-IR telescope. Decommissioned instruments include the Palomar Testbed Interferometer and the first telescopes at the observatory, an 18-inch (46 cm) Schmidt camera from 1936.

The South Coast is a region of California, making up roughly the southernmost quarter of the Californian coast.

A Southern California coastal bioregion is defined by California Environmental Resources Evaluation System (CERES) as including parts of six counties: the western section of Ventura, all of Orange, the majority of Los Angeles, the southwestern corner of San Bernardino, the western area of Riverside, and the majority of western San Diego. CERES calls this the South Coast Bioregion.

32°32′31.87″N 117°01′46.63″W / 32.5421861°N 117.0296194°W / 32.5421861; -117.0296194

San Diego–Tijuana is an international transborder agglomeration, straddling the border of the adjacent North American coastal cities of San Diego, California, United States, and Tijuana, Baja California, Mexico. The 2020 population of the region was 5,456,577, making it the largest bi-national conurbation shared between the United States and Mexico, and the second-largest shared between the US and another country. The conurbation consists of San Diego County, (2020 population 3,298,634) in the United States and the municipalities of Tijuana (2020 pop. 1,922,523), Rosarito Beach (126,980), and Tecate (108,440) in Mexico. It is the third-most populous region in the California–Baja California region, smaller only than the metropolitan areas of Greater Los Angeles and the San Francisco Bay Area.

Anza-Borrego Desert State Park (/ˈænzə bəˈreɪɡoʊ/, AN-zə bə-RAY-goh) is a California State Park located within the Colorado Desert of Southern California, United States. Created in 1932, the park takes its name from 18th century Spanish explorer Juan Bautista de Anza and borrego, a Spanish word for sheep. With 650,000 acres (260,000 ha) that includes one-fifth of San Diego County, it is the largest state park in California and the third largest state park nationally.

The park occupies eastern San Diego County and reaches into Imperial and Riverside counties, enveloping two communities: Borrego Springs, which is home to the park's headquarters, and Shelter Valley.