36 Old Ruins to Explore in California

4,163 acres (17 km²) park that includes the grounds of former mercury ("quicksilver") mines. The park is named after the New Almaden Quicksilver Mines, which were named after the mercury mine in (old) Almadén, Spain, and produced mercury that was used to process ore during the Gold Rush.

The Altaville Grammar School in Altaville, California is one of the oldest grammar schools in California. It was built in 1858 of brick in the Greek Revival style and remained in use until 1950, when it was replaced by the Mark Twain Elementary School in Altaville. After its abandonment, it fell into disrepair, but was restored in 1989 by the Calaveras County Historical Society. The building serves now as an example of a typical schoolroom of the 19th century.

This is a former mining and recreational property from the 1940s to the 1960s, it is infamous due to its association with Charles Manson and his "family". It is located inside Death Valley National Park in eastern California. There is a small one-room guest house located to the side of the main house. There is also a five-thousand-gallon "swimming pool" made from cement and rock boulders towards the back of the property.

Battery Spencer is a historic concrete military battery that today serves as an overlook above the Golden Gate Bridge and offers iconic and stunning views and photo opportunities. Photos taken of the Golden Gate Bridge from Battery Spencer have been some of the most iconic out there and featured on prints, postcards, and posters. The Battery was originally a gun battery from 1897 to 1942 and was named for a Revolutionary War hero.

The Butte Store stands as a solitary reminder of what was once a vibrant community. An Italian stone mason constructed the building in 1857 to serve settlers and miners as both their post office and general store.

This was the residence of the fifth commandant of the Presidio de Santa Barbara, José de la Guerra y Noriega, founder of the Guerra family of California. It is now a popular site for community and private events.The site is currently owned and operated by the Santa Barbara Trust for Historic Preservation as a historic house museum. The address is 15 East De la Guerra Street, Santa Barbara, California.

This is a massive Roman Catholic church in downtown San Jose, the cathedral of the Roman Catholic Diocese of San Jose, California, with the distinction of a minor basilica. It is listed as a California Historical Landmark and is listed on the National Register of Historic Places. The basilica is named for Saint Joseph, patron saint of the Catholic Church and namesake of San Jose, California.

The Cathedral of the Blessed Sacrament is considered one of three of the most historically significant buildings in Sacramento.As the mother church, it is the seat of Jaime Soto, the ordinary bishop of the Diocese of Sacramento. The Cathedral is located downtown at the intersection of 11th and K Streets. Currently, the cathedral is considered both a religious and civic landmark.

A historical site and living history center dedicated to restoring and preserving an awareness of the Chumash people and their historical, cultural, material and present-day influence, as well as the natural environment and historical significance of this site.

The First Congregational Church of Riverside is a historic church at 3504 Mission Inn Avenue in Riverside, California. It was designed by Myron Hunt, and built in 1913. It was added to the National Register in 1997.It is a two-story Spanish Colonial Revival building with a Latin cross plan with a 125 feet Churrigueresque style corner tower.

Fresno Dome is better defined by the Mono Indians as "the greeting place". The dome as known to the Mono Indians as "the greeting place". John Muir encountered Fresno Dome, calling it "Wamello", in the 1870s, and used its summit to locate Fresno Grove.The campground is a favorite spot for deer hunters and is largely empty other than during deer season.

Grace Cathedral is an Episcopal church in the heart of San Francisco. This is a house of prayer for all as we are a warm, diverse and an inviting congregat.The parish, which was founded in 1849, lost its previous church building in the 1906 San Francisco earthquake. The cathedral is famed for its mosaics by Jan Henryk De Rosen, a replica of Ghiberti's Gates of Paradise, two labyrinths, varied stained glass windows, Keith Haring AIDS Chapel altarpiece, and medieval and contemporary furnishings.

This is an art environment, located in Simi Valley, California. It was created by Tressa "Grandma" Prisbrey from the 1950s to the 1970s. Prisbey built a "village" of shrines, walkways, sculptures, and buildings from recycled items and discards from the local landfill. It has been designated as a historical landmark by the City of Simi Valley.

Greystone is one of the largest mansions in Beverly Hills and an important landmark for American cinema. It became a city park in 1971, and was subsequently added to the National Register of Historic Places in 1976 as Doheny Estate/Greystone. The house and grounds are often used as locations for film and television shows. The house's descending staircase is one of the most famous sets in Hollywood.

An abandoned borax mine. They became famous through the use of large twenty-mule teams and double wagons which hauled borax through the long overland route to the closest railroad in Mojave, California.

The Calaveras County Courthouse is a historic courthouse building in San Andreas, California. The brick courthouse was built in 1867 and contained the county's courtroom, jail, and sheriff's office; until 1888, executions were also conducted in the building. The Calaveras County Courthouse was added to the National Register of Historic Places on February 28, 1972.

Teh hisotory park in San Jose, California, USA is designed as an indoor/outdoor museum, arranged to appear as a small US town might have in the early 1900s. Since its inauguration in 1971, 32 historic buildings and other landmarks have either been moved from their original San Jose locations or are represented by replicas.

Kennedy Tailing Wheels Park is located at the transition point between Jackson Gate Road and North Main Street. This park preserves two of the remaining Kennedy Mine Tailing Wheels, the iconic symbols of the City of Jackson that were environmental pioneers during the hard rock mining era of the early 20th century.The park around these historical structures includes a kiosk with historical photographs and information about the engineering and operation of the wheels.

Mission San Francisco de Asís, commonly known as Mission Dolores, is a Spanish Californian mission and the oldest surviving structure in San Francisco. This historic structure features authentic adobe architecture and construction. It's a functioning Catholic Church and one of the oldest continuously operating churches in the nation.

Mission Basilica San Diego de Alcalá was the first of 21 Franciscan missions established in California. The mission and the surrounding area were named for the Catholic saint Didacus of Alcalá, a Spaniard more commonly known as San Diego. The current church, built in the early 19th century, is the fifth to stand on this location. The mission site is a National Historic Landmark.