Fort Funston is a popular coastal recreation spot just south of Ocean Beach and the San Francisco Zoo. Though the beach at Fort Funston is full of shells, its National Park status makes it illegal to collect them.
Fort Funston is part of the Golden Gate National Recreation Area, a network of protected lands in Northern California -- including Alcatraz and the Farralone Islands National Marine Sanctuary -- that are collectively a national park. Congress established the Golden Gate National Recreation Area (GGNRA) in 1972 following a proposal by U.S. Representative Philip Burton to protect coastal sites of historical and ecological significance in the San Francisco Bay Area.
Though the first national park was created in 1872, the National Park Service (NPS) did not exist until 1916 by an act of Congress approved by President Woodrow Wilson. The National Park Service's mission is "to conserve the scenery and the natural and historic objects and the wild life therein." To uphold this mission, the NPS prohibits collecting of shells, rocks, native plants and anything else you might find on the beach at Fort Funston (or in any other national park).
The United Nations has designated the GGNRA and other nearby sites as the Golden Gate Biosphere Reserve. Though this international status does not change the way U.S. regulations are enforced, it serves as an additional reminder to Fort Funston visitors of the site's significance and encourages them to leave shells, driftwood and native flowers undisturbed for the benefit of the local ecosystem, fellow visitors and future generations.