Centissima Reef

Sears Rock (sometimes Sear's Rock) is a small sub-surface rock about 0.7 miles (1.1 km) west of Rodeo Beach in the Pacific Ocean off Marin County, California. It is the highest point of the larger Centissima Reef, a sub-surface navigation hazard east of the Bonita Channel, although some reports refer to the two as separate features. A 1908 report on San Francisco Bay stated that a survey was then in progress to investigate the cost of removing both Sears Rock and Centissima Reef, along with Mission Bay Rock and Sonoma Rock, near Mission Rock in San Francisco Bay. In 1922, Representative Julius Kahn told a congressional committee that neither Sears Rock nor Centissima posed a navigation hazard as they had been blasted several years previously: "They are not visible, neither of them. The Sear's was blasted to a depth of 40 feet some five or six years ago. It is never visible at all. There are some people who think that it ought to be blasted to a depth of 45 feet, but the men who navigate the vessels think 40 feet for the present time a sufficient depth."

Rodeo Cove is an embayment in Marin County, California.

Tennessee Cove is an embankment off the Pacific Ocean in Marin County, California. It is named after the S.S. Tennessee, a steamship that ran aground near here on March 6, 1853. All 550 passengers climbed safely onto the beach, and fourteen chests of gold were salvaged before the ship broke up. Remnants of the ship can still be seen during low tide during some winter days on the south end of the beach. The cove is a 1.7-mile (2.7 km) hike from the parking lot near the end of Tennessee Valley Road.

The Golden Gate Raptor Observatory (GGRO) is a long-term program of the Golden Gate National Parks Conservancy in cooperation with the National Park Service. The GGRO's mission is to study migrating birds of prey along the Pacific coast and to inspire the preservation of raptor populations in California. Established in 1985, it is located in the Marin Headlands, just north of San Francisco, California. The Raptor Observatory operates under the philosophy that incorporating citizens into the process of gathering scientific data will deepen long-term conservation results. Consequently, the organization's small staff is supported by the work of 280+ highly trained volunteers, coming from all different disciplines. The GGRO publishes an annual report, contributes annual results to national databases, and collaborates on various research projects with local universities.

Bird Island is a small island between Point Bonita and Rodeo Cove in southern Marin County, California. It is located off the coast of Marin Headlands, about three miles from San Francisco.

Rodeo Beach ( roh-DAY-oh) is a beach in the Golden Gate National Recreation Area located in Marin County, California, United States, two miles north of the Golden Gate Bridge. It is characterized by a spit of around 50 meters width at the mouth of a long embayment, known as Rodeo Lagoon; for much of the year the lagoon is cut off from the ocean, making the beach spit a baymouth bar. Part of the beach is sheltered by cliffs. Rodeo Beach is known for its dark, pebbly sand, its uses for surfing and sunbathing, and its locale as a place for viewing, but not collecting, semi-precious stones. This beach is unique among California beaches in that it is largely made up of coarse, pebbly chert grains, both red and green in color. Its mineral composition sets it apart from every other beach in the state. Surfing is possible throughout the year and at all tidal stages, but is best in summer—although there is a risk of shark attacks. Due to the North bar offshore of this beach it results in big waves in the winter months with the big swells that come in. Strong currents make swimming dangerous. The beach features free entrance, free parking, wheelchair-accessible public restrooms, showers, and picnic tables. Dogs are allowed, but must be leashed or voice-controlled.In November 2007, oil from the wreck of the Cosco Busan washed up on Rodeo Beach, prompting its closure for several weeks.

Fort Cronkhite is one of the components of California's Golden Gate National Recreation Area. Today part of the National Park Service, Fort Cronkhite is a former US Army post that served as part of the coastal artillery defenses of the San Francisco Bay Area during World War II. The soldiers at Cronkhite manned gun batteries, radar sites, and other fortifications on the high ridges overlooking the fort.

Rodeo Lagoon is a coastal lagoon located in the Marin Headlands division of the Golden Gate National Recreation Area, which is in southern Marin County, California. This brackish water body is separated from the Pacific Ocean by a sand bar that forms Rodeo Beach. Rodeo Lagoon stretches approximately 900 metres (3,000 ft) by 250 metres (820 ft), and is about 2 metres (6.6 ft) deep at its maximum depth. It covers a surface area of about 15 hectares (37 acres).

The Marine Mammal Center (TMMC) is a private, non-profit U.S. organization that was established in 1975 for the purpose of rescuing, rehabilitating and releasing marine mammals who are injured, ill or abandoned. It was founded in Sausalito, California, by Lloyd Smalley, Pat Arrigoni and Paul Maxwell. Since 1975, TMMC has rescued over 24,000 marine mammals. It also serves as a center for environmental research and education regarding marine mammals, namely cetaceans (whales, dolphins and porpoises), pinnipeds (seals, fur seals, walruses and sea lions), otters and sirenians (manatees and dugongs). Marine mammal abandonment refers to maternal separation; pups that have been separated from their mother before weaning. At the center, they receive specialized veterinary care: they are diagnosed, treated, rehabilitated and ideally, released back into the wild. Animals in need of assistance are usually identified by a member of the public who has contacted the center. These animals represent the following major species: California sea lions, northern elephant seals, Pacific harbor seals, northern fur seals, Guadalupe fur seals, Hawaiian monk seals, and southern sea otters. On a few occasions, TMMC has taken in Steller sea lions and bottlenose/Pacific white-sided dolphins. The only non-mammals that TMMC takes in are sea turtles.

SF-88 is a former Nike Missile launch site at Fort Barry, in the Marin Headlands to the north of San Francisco, California, United States. Opened in 1954, the site was intended to protect the population and military installations of the San Francisco Bay Area during the Cold War, specifically from attack by Soviet bomber aircraft. The site was originally armed with Nike Ajax missiles, and modifications were made to the site in 1958 to allow it to also be armed with Nike Hercules missiles. In 1974, SF-88 was closed but was not demolished. It is now part of the Golden Gate National Recreation Area and is open to visitors. Visiting day is Saturday 12:30 - 3:30 PM, with formal tours occurring every 45 minutes. A special open house day with Nike veterans occurs on the first Saturday of each month. Restoration work to the site is done on remaining Saturdays by volunteers.

Point Bonita Lighthouse is a lighthouse located at Point Bonita at the San Francisco Bay entrance in the Marin Headlands near Sausalito, California. Point Bonita was the last manned lighthouse on the California coast. It was added to the National Register of Historic Places in 1991.

Fort Barry is a former United States Army installation on the West Coast of the United States, located in the Marin Headlands of Marin County, California, north of San Francisco. Opened 116 years ago in 1908, the fort was part of the Coast Artillery Corps and operated throughout the 20th century, before its closure and eventual transfer to the National Park Service.