Rancho San Diego, California Rancho San Diego, California Rancho San Diego is a census-designated place (CDP) in San Diego County, California. The population was 21,208 at the 2010 census, up from 20,155 at the 2000 census. The area was developed as subdivisions beginning in the 1970s. Rancho San Diego is located at (32.765985, -116.921477). According to the United States Census Bureau, the CDP has a total area of , all land. The chance of earthquake damage in Rancho San Diego is much lower than California average and is much higher than the national average. The risk of tornado damage in Rancho San Diego is
Old Town San Diego State Historic Park to the National Register of Historic Places as Old Town San Diego Historic District. The first European settlement on the West Coast of the present-day United States was the San Diego Presidio, a military outpost of Spanish California, founded by Gaspar de Portolà in 1769. Mission San Diego de Alcalá was founded by Father Junípero Serra the same year. The Presidio and Mission were originally built on a bluff above the San Diego River, Presidio Hill, which is now the site of the city-owned Presidio Park and which is immediately adjacent to Old Town State Historic Park. After five years