Del Mar (Spanish pronunciation: [del ˈmaɾ]; Spanish for "Of the Sea") is a beach town in San Diego County, California, located on the coast of the Pacific Ocean. Established in 1885 as a seaside resort, the city incorporated in 1959. The Del Mar Horse Races are hosted on the Del Mar racetrack every summer. In 1885, Colonel Jacob Taylor purchased 338 acres (1.37 km2) from Enoch Talbert, with visions of building a seaside resort for the rich and famous. The United States Navy operated a Naval Auxiliary Air Facility for blimps at Del Mar during World War II. The population was 3,954 at the 2020 census, down from 4,161 at the 2010 census.The town has a wealthy population along the coast and the bluffs above the ocean. These properties are very vulnerable to climate change, which has caused sea level rise and subsequent coastal erosion. The transportation infrastructure is under threat. The city has a climate change adaptation plan which notably excludes the option of a managed retreat, although the strategy was recommended by the California Coastal Commission in 2019.