SAN FRANCISCO — I have had a few occasions to spend some time in and around San Francisco. Most recently, that meant a trip to the Marin Headlands.

Located north and west of the Golden Gate Bridge, long-abandoned military batteries dot the hillside and are able to be examined up close and personal. I explored the Battery Mendel, so named for Army engineer Colonel George H. Mendel. An 1852 graduate of West Point, Mendel supervised the building of many Bay Area coastal fortifications with Battery Mendel completed in 1905, shortly after his retirement.

The battery was armed with two disappearing guns, long since removed, which would fold back out of sight when fired. While the guns may no longer be there, the original metal doors are still in place and show their 100-plus years of being exposed to the salt air.

Down the hill from Battery Mendel, located in the historic Fort Barry Chapel is the Marin Headlands Visitor Center. There one can learn about the Headland’s natural and human history, tracing the human history from the Miwoks through today.

One exhibit at the visitor center reveals just how close the Golden Gate Natural Recreation Area came to not existing at all. When the Army declared that entire region as surplus, developers were drooling at the opportunity to forever change the landscape. President Richard Nixon signed “An Act to Establish the Golden Gate National Recreation Area” on Oct. 27, 1972.

The road ends at Fort Cronkhite, a former World War II military post situated across the street from the beach. The military buildings of the era are preserved as well as others used for office space for the National Park Service.

The loop through the GGNRA comes down to the Golden Gate, giving majestic views of the bridge, San Francisco and the surrounding area. That vista has been used in many movies and television shows.

Coming back into San Francisco, directly underneath the Golden Gate is Fort Point. Originally constructed in the 1850s, some of the original cannons are still there.

There is much to offer in our back yard, and these attractions just scratch the service.

There is no charge to park or walk among the abandoned military fortifications.