The Silent Sentry

This past April, photographer Joseph Schell and two friends decided to find their way into Battery Construction 129, which they’d heard referenced as a sort of Holy Grail for local urban explorers. Declassified building schematics helped them narrow their hunt, and a History Channel clip provided a solid visual on the scene at the surface. After a failed day of searching, they eventually discovered and descended into the secret bunker, camera equipment in tow.

There, in absolute darkness lit only by their headlamps, they encountered an unusual scene: at least five decades’ worth of graffiti, a makeshift visitors’ journal on torn scraps of paper, and floors littered with both recent debris and scrap metal dating to the bunker’s original occupation in wartime. In a central chamber used by generations of kids for clandestine partying, they saw chairs arranged around concrete benches that had been draped in red-and-white-checkered picnic tablecloths. On and around the ersatz tables were empty wine and beer bottles, mason jars, a bucket, a golf club, cigarette butts, soda cans, candles and additional evidence of past soirees in the underworld.

It’s not easy to find Battery Construction 129, and once you do, it’s not easy to get in. First you must crawl backward through a gap (just big enough for a body) between the forest floor and a low concrete shelf — possibly the result of an earlier attempt by the National Park Service to keep people out. Once inside, you turn carefully to find a comparably expansive vertical ventilation shaft below, about six feet square and equipped with a rusted service ladder descending 75 feet into a black abyss. At the bottom is the cool, dank air of an underground world: 82,000 square feet of chambers and small rooms connected by stark concrete corridors, all buried beneath Hawk Hill in the Marin Headlands.

Of course, now you can’t get in at all. The World War II–era munitions bunker, long a treasured hideaway of Marin teenagers and urban explorers, has been sealed off — presumably for good. In July the National Park Service went to great lengths to ensure that no one would be able to access the space any longer, filling the air shaft with high-grade expansion foam, sealing the entrance with concrete and topping it all off with a fresh load of dirt.

The bunker will need that additional level of obscurity later this year when the park service sets out to remove 235 non-native Monterey pine and cypress trees from Hawk Hill. Their seeds were inadvertently transplanted by the army in soil used to cover the bunker in the early 1940s. Partly designed to restore habitat for the endangered Mission Blue butterfly, the project will convert what’s now a lush forest into coastal grassland in which any concrete structure would be hard to hide.

Golden Gate National Recreation Area spokesperson Howard Levitt says the timing of the landscaping with the sealing off of the bunker is just a coincidence. The tree work is intended to mitigate ecological impacts from road and trail construction elsewhere in the headlands, he says, and the bunker closure results from the park service’s recent discovery that members of the public were entering it more frequently. The agency decided to act both for safety’s sake and to protect the site from graffiti, which is already pervasive. “These are historic resources, and no one wants vandalism of a historic resource,” he says. “It’s a potentially serious safety hazard. It’s highly risky to enter bunkers.” According to Levitt, the bunker is unlikely to ever be accessible to the public again.

Interest in the bunker has grown since a film crew from the History Channel visited in 2009 — blindfolded and escorted by members of the Suicide Club, a San Francisco–based group known for elaborate pranks and public stunts that has explored and safeguarded the bunker since the late 1970s. Once word of Battery Construction 129’s closure got out, prospective and past visitors expressed their disappointment. In a forum on a website called Urban Exploration Resource, online users kvetched: “I never even had a chance to go;” “I just found this bunker last week;” and “It only takes one moron to ruin things for everyone.”

Decades ago, Joshua Nelson visited the bunker — and at least a dozen others in the Headlands — as a teenager growing up in Marin. Now 40 and living near Fairfax, he’s sad to think of Battery Construction 129 being lost, although he’s not so sure the closure will even work. “It’s like trying to bury a pyramid,” he said. “The more they try to hide it and bury it, the more people are going to be drawn to it.”

Perhaps part of the attraction is the story behind the batteries, which tells of a fascinating time in U.S. history when the country was convinced a West Coast attack was coming by sea. Taking their place in a long line of coastal fortifications built to defend the Golden Gate, both Townsley and Construction 129 were designed to house the latest in heavy-duty marine artillery: a pair of massive guns with 16-inch barrels. The guns and their magazines, power rooms and crew (the weapons were the size of a truck and required many hands to operate) were kept safe and out of sight in the bunkers.

On July 1, 1940, the first 16-inch round ever fired from the Pacific Coast of the continental U.S. went off at Battery Townsley. The 2,100-pound projectile was expected to sail five miles beyond the Farallones, but it went even further — more than 30 miles from the coast. The whole mountain shook with the gun’s force. Battery Townsley and its counterpart, Battery Davis, built around the same time on the south side of the Golden Gate at Fort Funston, became prototypes for the army’s planned new coastal defense system.

Despite the considerable effort required, the army was so assured of its vulnerability that it planned to install at least 25 more 16-inch gun batteries along both coasts. The building of Battery Construction 129, located at Fort Barry, began in June 1941. It was built even more heavily than Townsley and Davis, and it quickly became one of the busier bunkers among the many in the Marin Headlands.

Yet after it became clear that the Japanese would not be attacking American ports, construction on the still-unnamed battery came to a halt in November 1943; it was closed up and classified “suspended.” And while the basic structure and much of the interior infrastructure — distributed across an area at least 500 feet long — was already complete, including a kitchen, living quarters and arms storage, it would never be used again. Its massive guns, delivered but never installed, ended up on the scrap heap.

Today, the only remaining signs of the facility’s intended use are deteriorating communications, plumbing, and electrical lines and fixtures scattered throughout — plus a rusted overhead rail, once capable of carrying heavy artillery.

Even with the recent news of its closure, some adventurers are using online forums to plot their way back into Construction 129. It may all be idle talk, given the lengths the National Park Service has gone to keep them out. But their attitude reveals the appeal of the unknown, the powerful pull of the forbidden, that has attracted people to the bunker for decades. For now it waits, dark and empty, like an alluring concrete time capsule.

BUNKER EXPLORATION Those looking to enter a bunker in a safe, clean and legally sanctioned setting are not out of luck. Fort Cronkhite’s restored Battery Townsley, similar in size and function to Battery Construction 129 and located only a mile to the north, is open to the public on the first Sunday of each month from noon to 4 p.m.