Over 39 million vehicles a year travel across a famous bridge—and pass over an NPS historic site, both literally and figuratively. The park under the bridge is often overlooked by locals and tourists alike, but it offers both interesting history and a fine scenic view.

Tucked away under the Golden Gate Bridge, the impressive structure that gives Fort Point National Historic Site its name has been called "the pride of the Pacific," "the Gibraltar of the West Coast," and "one of the most perfect models of masonry in America."

The fort's location inevitably leads to questions like the one overheard at the park several years ago by Traveler reader Kathy Grogman: "Why did they build a fort underneath the Golden Gate Bridge?"

Even in our post-9/11 world, the official answer is not, "It's part of the Homeland Security System," and there's no doubt about which came first—the fort or the bridge. Nonetheless, the Homeland Security angle wouldn't be too far afield from a historical standpoint. A park publication notes:

Fort Point was built between 1853 and 1861 by the U.S. Army Engineers as part of a defense system of forts planned for the protection of San Francisco Bay. Designed at the height of the Gold Rush, the fort and its companion fortifications would protect the Bay's important commercial and military installations against foreign attack.

The fort was built in the Army's traditional "Third System" style of military architecture (a standard adopted in the 1820s), and would be the only fortification of this impressive design constructed west of the Mississippi River. This fact bears testimony to the importance the military gave San Francisco and the gold fields during the 1850s.

In a bit of irony, a key part of a fort built to defend San Francisco from "foreign attack" was imported from China. In "Fort Point: Sentry at Golden Gate," historian John Martini notes:

Finding the necessary building materials at reasonable prices became a never-ending problem for the engineers overseeing the project. Very few of the sources of brick and stone in California met the Army’s high standards for use in fortifications...

In late 1854, the supervising engineer at Fort Point finally secured permission to use granite imported from China in the work’s foundations; it was of better quality than anything he had been able to find in California, and it cost less than local stone despite being shipped over 5,000 miles.

A shot was never fired in battle from Fort Point, and although it survived the San Francisco Earthquake in 1906, it nearly fell victim to "progress" in the 1930s, during construction of the Golden Gate Bridge. According to historian Martini, the fort was saved by an engineer with a sense of history:

Chief Engineer Joseph Strauss initially concluded that Fort Point sat on the optimal location for a huge concrete caisson anchoring the bridge’s San Francisco end. After touring the empty fort, however, he changed his mind. He wrote...“While the old fort has no military value now, it remains nevertheless a fine example of the mason’s art. Many urged the razing of this venerable structure to make way for modern progress. In the writer’s view it should be preserved and restored as a national monument…”

It took more than three decades before Strauss' recommendation was finalized; Fort Point was designated a national historic site in 1970.

You can tour the fort on your own when it's open, or take advantage of a guided tour or other programs. The park website has details to help plan a visit.

Due to work underway on the Golden Gate Bridge, Fort Point is currently open only on Fridays, Saturdays, and Sundays from 10 a.m. to 5 p.m. As the staff points out on the park website, "When you're working on something above you, it is good to make sure there is no one below."