From wikipedia: Olivenhain is a neighborhood in the city of Encinitas, California, located in the North County area of San Diego County. It is the eastern-most community of Encinitas, bordering the western portion of Rancho Santa Fe. Originally an unincorporated community, in 1986 it joined with five other communities to form the city of Encinitas.
The community of Olivenhain is primarily single family custom homes with relatively large lots. Minimum lot sizes range from 0.5 acres (2,000 m2) to 5 acres (20,000 m2). The topography tends to be rolling, and most streets are small and winding through the hills.
The area is located on the Rancho Las Encinitas Mexican land grant, and was settled by a German colony in the 1890s. The name Olivenhain is from the German and means “olive grove”. The German settlers built the meeting hall which still stands. It is used today for community functions such as the annual Oktoberfest, Haunted House, summer movie series, craft fairs and a variety of civic group meetings. Residents of Olivenhain may schedule the Meeting Hall and grounds for private functions; it is a popular wedding site.
Olivenhain has a vast network of recreational trails, used by walkers and equestrians. A common sight in the area during late afternoons and dusk are hot air balloons.
Olivenhain has a darker sky than coastal San Diego towns due to its “Dark Sky Policy” which restricts lights from street lights, tennis courts, and other forms of light pollution.