Settlements similar to or like San Diego

County in the southwestern corner of the state of California, in the United States. 3,095,313, making it California's second-most populous county and the fifth-most populous in the United States. Wikipedia

Second-largest city in the San Diego metropolitan area, the seventh largest city in Southern California, the fifteenth largest city in the state of California, and the 75th-largest city in the United States. 243,916 as of the 2010 census, and the estimated population as of 2019 is 274,492. Wikipedia

State in the Pacific Coast region of the United States. Most populous U.S. state and the third-largest by area, as well as the world's thirty-fourth-most-populous subnational entity. Wikipedia

International transborder agglomeration, straddling the border of the adjacent North American coastal cities of San Diego, California, United States and Tijuana, Baja California, Mexico. 4,922,723, making it the largest bi-national conurbation shared between the United States and Mexico, the second-largest shared between the US and another country. Wikipedia

Largest city in California. Estimated population of nearly four million people, it is the second most populous city in the United States and the third most populous city in North America (after Mexico City and New York City). Wikipedia

Cultural, financial, and political center of Silicon Valley, and the largest city in Northern California by both population and area. Estimated 2019 population of 1,021,795, it is the third-most populous city in California and the tenth-most populous in the United States. Wikipedia