San Diego, California — Travel Guide & Things to Do

San Diego (/ˌsæn diˈeɪɡoʊ/ SAN dee-AY-goh, Spanish: ; Spanish for 'Saint Didacus'; Tepacul Watai (Kumiai for 'Stacked big'); Pushuyi in Luiseño/Chamꞌteela) is a city in the U.S. state of California located alongside the Pacific Ocean in Southern California. With a population of over 1.3 million residents, the city is the eighth-most populous in the United States and the second-most populous in California after Los Angeles. The city is located immediately adjacent to the Mexico–United States border and is the seat of San Diego County, which has a population of nearly 3.3 million people as of 2021. San Diego is known for its mild year-round Mediterranean climate, extensive beaches and parks, its long association with the United States Navy, and its recent emergence as a healthcare and biotechnology development center.