Now administered by the “Presidio Trust”

Prior to Sixth Army leaving in 1994, the Presidio of San Francisco was if not the oldest then one of the oldest military installations still in use within the United States. It was originally established by Spanish Captain Juan Bautista de Anza in 1766. Subsequently (and briefly) run by Mexico and then by the one-time California Republic (aka Bear Flag revolt) and ultimately by the USA (ergo the phrase: "under four flags"). For those that were fortunate to serve here, most would agree it was one of the most beautiful bases in the Army's real estate portfolio. Still a gorgeous place to visit.

More on Wiki (and elsewhere):

O-Club - After Sixth Army left and the "Presidio Trust" took over The Presidio Officers' Club (i.e., the oldest building in San Francisco) and it has been renovated and repurposed into a gathering place w/exhibits and a restaurant.

Fort Point (at base of the Golden Gate Bridge). When last checked the fort is only open on weekends. Provides the best views of the GG Bridge. Still a great place to walk around even when it's closed.

Presidio Golf Course (and formerly Presidio Army Golf Course) - Ike, Teddy and other luminaries played here.

Surfing @ the Fort Point break. Wet suit required - it's cold and watch out for the rock lined shore!

Plenty of details at:

Decent eats here (and elsewhere on the grounds):

NorCal California. What's not to like? One of the most beautiful areas in California.

The San Francisco/Silicon Valley/Marin County area has some of the highest real estate and rental prices in the United States. Even the East Bay costs a lot of coin now.