Mount Diablo

The Mount Diablo meridian, established in 1851, is a principal meridian extending north and south from its initial point atop Mount Diablo in California at W 121° 54.845. Established under the U.S. Public Land Survey System, it is used to describe lands in most of northern California and all of Nevada. Mount Diablo also marks the baseline at latitude 37°52′54″N.

The Athenian School is a selective college preparatory and boarding school located in Danville, California, United States. Athenian educates students in grades 6–12 on an approximately 75-acre (300,000 m2) campus at the base of Mt. Diablo, located in the San Francisco Bay Area in Northern California. Athenian was founded by Dyke Brown in 1965. Athenian is composed of roughly 170 students in the middle school (grades 6–8) and 360 students in the high school (9–12), which is also known as the upper school. Approximately 60 students and 18 teachers live on campus full-time. The average class size is 14. According to Niche, Athenian is ranked 147th on the 2020 list of Best Private High Schools in America and the number one school in Contra Costa County. Athenian is also ranked as the 40th best boarding school in the United States.Athenian holds an average SAT score of 1385 (out of 1600) and an average ACT score of 32. According to Boarding School Review, this gives Athenian the 8th highest SAT score of any boarding school in the United States.

Contra Costa County ( ; Contra Costa, Spanish for "Opposite Coast") is a county located in the U.S. state of California, in the East Bay of the San Francisco Bay Area. As of the 2020 United States Census, the population was 1,165,927. The county seat is Martinez. It occupies the northern portion of the East Bay region of the San Francisco Bay Area and is primarily suburban. The county's name refers to its position on the other side of the bay from San Francisco. Contra Costa County is included in the San Francisco–Oakland–Berkeley, CA Metropolitan Statistical Area.

Blackhawk is an unincorporated planned community and census-designated place located in Contra Costa County, California, United States, east of Danville and Oakland. As of the 2010 census it had a population of 9,354. Governed by county rules/regulations and a homeowner association (HOA), Blackhawk has a country club, two golf courses, sports complex, restaurants, and the adjacent Blackhawk Plaza. 24-hour security plus additional law enforcement contracted through the Contra Costa County Sheriff's Office is provided by HOA dues. The area is covered by the San Ramon Valley Fire Protection District. The ZIP code is 94506. The community is inside area code 925. Blackhawk is known for its uniform architecture and suburban lifestyle, with the median household income being $167,875 and median home price of $1,117,500.

Marsh Creek Springs was a private recreational facility in Contra Costa County, California. It was developed in 1927 by Gerald L. Gill on 90 acres alongside Marsh Creek. The facility included two swimming pools, wading pools, a livery stable, a dance hall and four baseball diamonds. By 1940 it had grown to cover 210 acres and was able to host 5,000 guests and 1,200 automobiles arriving from all over the Bay Area. In 1957 a flash flood sent a twelve-foot crest of water down Marsh Creek and destroyed the park. It was re-opened that same year but a second flood in 1962 again destroyed the park and it remained closed.

Clayton (formerly Clayton's and Claytonville) is a city in Contra Costa County, California, United States. The population was 11,585 as of the 2020 census.

Diablo (Spanish for "Devil") is a census-designated place (CDP) in Contra Costa County, California, United States. The population was 1,158 at the 2010 census. It is located 2.5 miles (4.0 km) east-northeast of Danville.

The Hemme Hills are a mountain range in Contra Costa County, California.

Blackhawk-Camino Tassajara is a former census-designated place (CDP) in Contra Costa County, California, near the town of Danville. The unincorporated area consisted of the Blackhawk planned community and the surrounding Camino Tassajara area. At the 2000 census, the CDP's population was 10,048. The CDP was split between Blackhawk and Camino Tassajara before the 2010 census.

Sycamore Valley Regional Open Space Preserve is a regional park in Contra Costa County, California, outside of Danville, California, United States that is part of the East Bay Regional Parks (EBRPD) system.

Castle Rock Regional Recreation Area is a 18,000 acres (73 km2) regional park of the East Bay Regional Park District. It is located in Contra Costa County, in the East Bay region of northern California.

Monte Vista High School is a comprehensive public high school located in Danville, California, United States. It is a National Blue Ribbon school, as well as a California Distinguished School. It is fully WASC accredited. The school is located in the San Ramon Valley, approximately 35 miles (56 km) east of San Francisco, and is part of the San Ramon Valley Unified School District. Their school mascot is a mustang.