Castro Valley Unified School District

Redwood High School is an alternative/continuation public high school in Castro Valley, California, United States. It is the only alternative/continuation high school in Castro Valley, and is one of only two high schools in Castro Valley, the other being Castro Valley High School. Redwood High School was remodeled from 2006 to 2008.

Eden Medical Center is a hospital and medical center located in Castro Valley, California, providing emergency medical services to Alameda County. It is operated by Sutter Health. It is built on an elevated area, and is visible from a distance.

The 1868 Hayward earthquake occurred in the San Francisco Bay Area, California, United States on October 21. With an estimated moment magnitude of 6.3–6.7 and a maximum Mercalli intensity of IX (Violent), it was the most recent large earthquake to occur on the Hayward Fault Zone. It caused significant damage and a number of deaths throughout the region, and was known as the "Great San Francisco earthquake" prior to the 1906 San Francisco earthquake and fire.

Area codes 510 and 341 are telephone area codes in the North American Numbering Plan (NANP) serving much of the East Bay in the U.S. state of California. They cover parts of Contra Costa County and western Alameda County, including the city of Oakland, but excluding Dublin, Livermore, Pleasanton, and Sunol. Area code 510 was established on September 2, 1991, in a split from area code 415. On March 4, 1998, the inland portion of the East Bay was split off as area code 925. The dividing line followed the Berkeley Hills; almost everything west of the hills stayed in 510, while everything east of the hills transferred to 925. In response to projections that 510 would exhaust in the second quarter of 2019, the California Public Utilities Commission approved the addition of an overlay area code, 341, to serve the East Bay. The first central office codes in 341 became available on July 22, 2019.Ten-digit dialing became mandatory in the East Bay a month earlier, on June 22.

Rancho San Lorenzo was a 26,722-acre (108.14 km2) Mexican land grant given in 1841 by Governor Juan Alvarado to Guillermo Castro a career soldier posted to the Pueblo of San José. The land grant included present day Hayward, San Lorenzo, and Castro Valley, including Crow Canyon, Cull Canyon, and Palomares Canyons.

Castro Valley High School is located in the unincorporated suburban community of Castro Valley, California, United States. It is a State school#United States high school for grades 9 to 12. Named a National Exemplary School in 1984–85 and 1988–89, it was a California Distinguished School in 1987–88, 2000–01, and 2009.It is part of the Castro Valley Unified School District.

Castro Valley is a census-designated place (CDP) in Alameda County, California, United States. At the 2010 census, it was the fifth most populous unincorporated area in California and the twenty-third most populous in the United States. The population was 66,441 at the 2020 census.Castro Valley is named after Don Guillermo Castro, a noted 19th-century Californio ranchero who owned the land where the community is located.

Guadalupe Creek or Guadalupe Valley Creek is a short eastward-flowing stream whose watershed originates just east of the highest peak of San Bruno Mountain in San Mateo County, California, United States. It courses through San Bruno Mountain State and County Park and Brisbane before entering the Brisbane Lagoon.

John George Psychiatric Hospital, previously John George Psychiatric Pavilion, also known as John George Psychiatric Emergency Room, John George Hospital or John George, is a psychiatric hospital located in San Leandro, in Alameda County, California. It is operated by the Alameda Health System. It is located near Fairmont Hospital and the county Juvenile Justice Center. It opened in 1992 and was named after County Supervisor John George to honor his advocacy for mentally ill people. It has an 80-bed capacity. In November 2003, a doctor at the facility, Erlinda Ursua, died there and a patient, a 38-year-old female was charged with murder. The female patient pled not guilty in 2005. No criminal charges were later filed.

Lake Chabot Regional Park is a regional park located in the southern Berkeley Hills in Alameda County, California. It is part of the East Bay Regional Parks system. Lake Chabot is a reservoir located in the park. The northern part of the lake and park lie within the boundary of the City of Oakland, while the southern part lies in an unincorporated area of Alameda County adjacent to Castro Valley and San Leandro. The dam and reservoir's water are part of the East Bay Municipal Utility District (EBMUD) water system.

Castro Valley is a BART station located in the center median of Interstate 580 in Castro Valley, California. The entrance plaza, parking lots, and bus transfer area are located on the north side of the highway; a tunnel under the westbound lanes connects the entrance to the fare lobby, which is located under the island platform. The station opened on May 10, 1997, as part of the extension to Dublin/Pleasanton station.

Ashland is a census-designated place (CDP) and unincorporated community in Alameda County, California, United States. The population was 23,823 at the 2020 census. Ashland is located between the city of San Leandro to the north, the unincorporated community of Cherryland to the south, the unincorporated community of Castro Valley to the east, and the unincorporated community of San Lorenzo to the southwest. Ashland shares a postal zip code with the neighboring unincorporated community of San Lorenzo to the southwest, as well as the close by cities of Hayward to the south and San Leandro to the north. There is no documented evidence that Ashland was ever known as “San Leandro South” but instead has been informally, albeit incorrectly, known as "unincorporated San Leandro" or "unincorporated Hayward" since Ashland does not have its own postal zip code designation.