Fort Point , San Francisco Fort Point is a masonry seacoast fortification located at the southern side of the Golden Gate at the entrance to San Francisco Bay . This fort was completed just before the American Civil War by the United States Army , to defend San Francisco Bay against hostile warships . The fort is now protected as Fort Point National Historic Site , a United States National Historic Site administered by the National Park Service as a unit of the Golden Gate National Recreation Area . History . In 1769 Spain occupied the San Francisco area and by 1776 had established the area ' s first European settlement , with a mission and a presidio . To protect against encroachment by the British and Russians , Spain fortified the high white cliff at the narrowest part of the bay ' s entrance , where Fort Point now stands . The Castillo de San Joaquin , built in 1794 , was an adobe structure housing nine to thirteen cannons . Mexico won independence from Spain in 1821 , gaining control of the region and the fort , but in 1835 the Mexican army moved to Sonoma leaving the castillo ' s adobe walls to crumble in the wind and rain . On July 1 , 1846 , after the Mexican - American War broke out between Mexico and the United States , U . S . forces , including Captain John Charles Fremont , Kit Carson and a band of 10 followers , captured the empty castillo and spiked ( disabled ) the cannons . U . S . Era . Following the United States ' victory in 1848 , California was annexed by the U . S . and became a state in 1850 . The gold rush of 1849 had caused rapid settlement of the area , which was recognized as commercially and strategically valuable to the US . Military officials soon recommended a series of fortifications to secure San Francisco Bay . Coastal defenses were built at Alcatraz Island , Fort Mason , and Fort Point . The U . S . Army Corps of Engineers began work on Fort Point in 1853 . Plans specified that the lowest tier of artillery be as close as possible to water level so cannonballs could ricochet across the water ' s surface to hit enemy ships at the water - line . Workers blasted the cliff down to above sea level . The structure featured seven - foot - thick walls and multi - tiered casemated construction typical of Third System forts . It was sited to defend the maximum amount of harbor area . While there were more than 30 such forts on the East Coast , Fort Point was the only one on the West Coast . In 1854 Inspector General Joseph K . Mansfield declared " this point as the key to the whole Pacific Coast . . . and it should receive untiring exertions " . A crew of 200 , many unemployed miners , labored for eight years on the fort . In 1861 , with war looming , the army mounted the fort ' s first cannon . Colonel Albert Sidney Johnston , commander of the Department of the Pacific , prepared Bay Area defenses and ordered in the first troops to the fort . Kentucky - born Johnston then resigned his commission to join the Confederate Army ; he was killed at the Battle of Shiloh in 1862 . Fort Point and the Civil War . Throughout the Civil War , artillerymen at Fort Point stood guard for an enemy that never came . The Confederate raider CSS " Shenandoah " planned to attack San Francisco , but on the way to the harbor the captain learned that the war was over ; it was August 1865 , months after General Lee surrendered . Severe damage to similar forts on the Atlantic Coast during the war - Fort Sumter in South Carolina and Fort Pulaski in Georgia - challenged the effectiveness of masonry walls against rifled artillery . Troops soon moved out of Fort Point , and it was never again continuously occupied by the army . The fort was nonetheless important enough to receive protection from the elements . In 1869 a granite seawall was completed . The following year , some of the fort ' s cannon were moved to Battery East on the bluffs nearby , where they were more protected . In 1882 Fort Point was officially named Fort Winfield Scott after the famous hero from the war against Mexico . The name never caught on and was later applied to an artillery post at the Presidio . Into a new century . In 1892 , the army began constructing the new Endicott System concrete fortifications armed with steel , breech - loading rifled guns . Within eight years , all 103 of the smooth - bore cannons at Fort Point had been dismounted and sold for scrap . The fort , moderately damaged in the 1906 earthquake , was used over the next four decades for barracks , training , and storage , however , in 1913 , part of the interior wall was removed by the army in their short - lived attempt to make the fort the army detention barracks using soldier and prisoner labor . The detention barracks were later built on Alcatraz Island and was used until becoming a federal prison . Soldiers from the 6th U . S . Coast Artillery were stationed there during World War II to guard minefields and the anti - submarine net that spanned the Golden Gate . Preserving Fort Point . In 1926 the American Institute of Architects proposed preserving the fort for its outstanding military architecture . Funds were unavailable , and the ideas languished . Plans for the Golden Gate Bridge in the 1930s called for the fort ' s removal , but Chief Engineer Joseph Strauss redesigned the bridge to save the fort . " While the old fort has no military value now , " Strauss said , " it remains nevertheless a fine example of the mason ' s art . . . It should be preserved and restored as a national monument . " The fort is situated directly below the southern approach to the bridge , underneath an arch that supports the roadway . Preservation efforts were revived after World War II . On October 16 , 1970 , President Richard Nixon signed a bill creating Fort Point National Historic Site . Landmark status . Fort Point is designated as California Historical Landmark # 82 , officially listed under the site ' s original name , Castillo De San Joaquín . Recreation . The rocky point north of the fort produces a wave , in the winter months , that is popular with surfers . Media use . Fort Point is a popular filming location . It is also mentioned in other media .