Olivenhain is a neighborhood in the city of Encinitas, California, located in the North County area of San Diego County. It is the easternmost community of Encinitas, bordering the western portion of Rancho Santa Fe. The community of Olivenhain is primarily single family custom homes with relatively large lots. Minimum lot sizes range from 0.5 acres to 5 acres. The topography tends to be rolling, and most streets are small and wind through the hills.