Black Hills (Contra Costa County)

Briones Reservoir is an open cut terminal water storage reservoir located in western Contra Costa County, in the East Bay region of the San Francisco Bay Area, California. It is owned and operated by the East Bay Municipal Utility District (EBMUD).

The Briones Valley is a major geological feature of Contra Costa County, California and runs between Mount Diablo and the county seat of Martinez. Also, it is the seat of many riparian watersheds, especially of Alhambra Creek.

The Charles W. Merrill House is a 6,000-square-foot residence built in 1938 and located in Orinda, California. Designed by regionally prominent architect Walter H. Ratcliff, of Berkeley, California for mining engineer and San Francisco businessman Charles Washington Merrill.

Rancho Laguna de Los Palos Colorados was a 13,316-acre (53.89 km2) Mexican land grant in the Berkeley Hills (then called the Sierra de la Contra Costa, "Contra Costa Range") within present-day Contra Costa County, California. It was given in 1841 by Governor Juan Alvarado to Joaquín Moraga and his cousin, Juan Bernal. The name means "Ranch of the Lake of the Redwoods" in Spanish. The rancho included the present-day Orinda, Lafayette and Moraga, as well as the communities of Canyon and Rheem.

Holden High School is a private, non-profit school located in Orinda, Contra Costa County, California, United States. Founded in 1969, it is accredited by the Western Association of Schools and Colleges and its diplomas are recognized by the State of California. The students are from all over the San Francisco Bay Area, and reflect the area's diversity.

Orinda Academy (OA) is a secondary school located in Orinda, California, United States.

Rancho Boca de la Cañada del Pinole was a 13,316-acre (53.89 km2) Mexican land grant in present-day Contra Costa County, California given in 1842 by Governor Juan Alvarado to María Manuela Valencia. The name means "Mouth of the Pinole Valley" in Spanish. The rancho located between present-day Martinez, Pleasant Hill, Orinda, and Lafayette.

Rancho El Sobrante was a 20,565-acre (83.22 km2) Mexican land grant in present-day Contra Costa County, California given in 1841 by Governor Juan Alvarado to Juan Jose Castro and Victor Castro. The name refers to a "surplus" in Spanish—the grant's boundaries were determined by the boundaries of the surrounding grants: San Antonio, San Pablo, El Pinole, La Boca de la Cañada del Pinole, Acalanes, and La Laguna de los Palos Colorados. This grant included the area between present day El Sobrante and Orinda.

Leuschner Observatory, originally called the Students' Observatory, is an observatory jointly operated by the University of California, Berkeley and San Francisco State University. The observatory was built in 1886 on the Berkeley campus. For many years, it was directed by Armin Otto Leuschner, for whom the observatory was renamed in 1951. In 1965, it was relocated to its present home in Lafayette, California, approximately 10 miles (16 km) east of the Berkeley campus. In 2012, the physics and astronomy department of San Francisco State University became a partner. Presently, Leuschner Observatory has two operating telescopes. One is a 30-inch (760 mm) optical telescope, equipped with a CCD for observations in visible light and an infrared detector used for infrared astronomy. The other is a 12-foot (3.7 m) radio dish used for an undergraduate radio astronomy course. The observatory has been used to perform professional astronomy research, such as orbit determination of small solar system bodies in the early 1900s and supernova surveys in the 1980s and 1990s. It has also served as a primary tool in the education of graduate and undergraduate students at UC Berkeley.

Orinda is a city in Contra Costa County, California, United States. The city's population as of the 2020 census is estimated at 19,514 residents.

Lake El Toyonal (Spanish: Lago El Toyonal) is a small lake in Contra Costa County, California in an unincorporated area of parklands between Orinda and Berkeley.

Orinda station is a Bay Area Rapid Transit station in Orinda, California. The station has an island platform in the center median of State Route 24. Service at the station began on May 21, 1973, following the completion of the Berkeley Hills Tunnel, which connects it to Rockridge station. An abstract mural by Win Ng, partially covered by advertisements, is located in the fare lobby.In 2008, BART added solar panels over parking areas at Orinda station, as well as the Richmond and Hayward maintenance yards. The $3.8 million project was expected to provide all station electrical needs during daylight hours.The elevator to the platform is outside of the paid area. BART plans to add a dedicated faregate for the elevator in 2022.