Volcanic eruptions on the Medicine Lake shield volcano have created an incredibly rugged landscape punctuated by cinder cones, lava flows, spatter cones, lava tube caves and pit craters. During the Modoc War of 1872-1873, the Modoc Indians used these tortuous lava flows to their advantage. Under the leadership of Captain Jack, the Modocs took refuge in "Captain Jack's Stronghold," a natural lava fortress. From this base a group of 53 fighting men and their families held off US Army forces numbering up to ten times their strength for five months. Visitors can tour both the geologic and historic wonders of this unusual landscape. The Lava Beds are located in Tulelake, California.

For thousands of years, Native Americans called the Ohlone managed and harvested the natural bounty of what is now the Presidio. In 1776, Spanish soldiers and missionaries arrived, forever disrupting Ohlone culture and beginning 218 years of military use of the area just south of the Golden Gate. The Presidio served as a military post under the flags of Spain (1776-1822), Mexico (1822-48), and the United States (1848-1994). Today, visitors enjoy the history and beauty of the Presidio. Within its boundaries are more than 500 historic buildings, a collection of coastal defense fortifications, a national cemetery, an historic airfield, a saltwater marsh, forests, beaches, native plant habitats, coastal bluffs, miles of hiking and biking, and some of the most spectacular vistas in the world.

The Golden Gate National Recreation Area (GGNRA) is one of the largest urban national parks in the world. GGNRA’s 75,398 acres of land and water extend north of the Golden Gate Bridge to Tomales Bay in Marin County and south to San Mateo County, encompassing 59 miles of bay and ocean shoreline. The park contains numerous historical and cultural resources, including Alcatraz, Marin Headlands, Nike Missile Site, Fort Mason, as well as Muir Woods National Monument, Fort Point National Historic Site, and the Presidio of San Francisco. These sites contain a variety of archeological sites, military forts and other historic structures which present a rich chronicle of two hundred years of history, including Native American culture, the Spanish Empire frontier, the Mexican Republic, evolution of American coastal fortifications, maritime history, 18th century and early 20th century agriculture, military history, California Gold Rush, Buffalo Soldiers, and the growth of urban San Francisco. Golden Gate National Recreation Area is also rich in natural resources—it is comprised of 19 separate ecosystems in 7 distinct watersheds and is home to 1,273 plant and animal species. With 80 sensitive, rare, threatened, or endangered species —including the Northern Spotted Owl, California Red-legged Frog, and Coho Salmon— the park has the fourth largest number (33) of federally protected or endangered species of all units in the National Park System.