Rancho San Lorenzo

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.

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.

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.

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.

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.

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.

The Hayward Japanese Gardens, located near downtown Hayward, are the oldest Japanese gardens in California designed along traditional lines. They are maintained by the Hayward Area Recreation and Park District (HARD).

Cull Canyon Regional Recreation Area (CCRRA) is a regional park located in Castro Valley, Alameda County, California. It is part of the East Bay Regional Park District (EBRPD) system.

The City Center Building, known briefly as Centennial Tower, was the tallest building in Hayward, California. It was previously the second tallest, until the 2013 razing of Warren Hall on the Cal State East Bay campus. It was for many years an abandoned building, located between Foothill Boulevard and City Center Drive, in the City Center section of Downtown Hayward, adjacent to the PlazaCenter mall. It was formerly used as Hayward City Hall.Demolition of the building began in January 2020 and was completed by September 2020.

Cull Creek is a 7.5 mile long creek in Contra Costa and Alameda Counties, California. It is a tributary to Crow Creek, which is itself a tributary to San Lorenzo Creek.