Many years ago, around the turn of the millennium, as I was simultaneously just breaking into and away from the San Francisco underground art scene, some folks I used to run with said elusive phantom stranger John Law had called for a bunch of us to meet up for mysterious purposes, as he was wont to do.

Hopping into some cars that night, we caravaned out along the twisty road into the Marin Headlands, parking some distance from Hawk Hill and walking there under cover of night. Once we arrived at the observation platform on top of the hill, someone produced a shovel and began to dig in the dirt, down a foot or two until hitting a rock. We pulled the rock out, and, to my surprise, underneath was an overturned 5-gallon bucket. We pulled out the bucket, and under that, to my greater surprise, was a narrow hole, going down into the ground and turning horizontally towards parts unknown. One by one, people started crawling head-first into the hole, like a rodent, straight down into the ground.

To give you an idea, I’m not a big guy physically, but that night I happened to be wearing a leather motorcycle jacket, and the hole was just big enough to admit me and the jacket’s bulk… small enough that one guy was uneasy, and volunteered to sit watch rather than crawl down into this mysterious, claustrophobic underground passage, missing out on everything that followed.

Crawling into the hole myself, I found that it quickly opened into a horizontal gap in the ground just big enough for an adult to crawl through. Crawling a few feet through this dirt cave, suddenly, to my left were two concrete slaps, with just enough vertical distance between them for an adult to fit through. Sticking me head in and shining my flashlight down, I saw a concrete shaft leading down maybe 30 feet, with a caged rebar ladder running down once side it. It was down this ladder that those who crawled into the whole before me had disappeared down. I climbed down it.

The below photojournal is of what I saw at the bottom of that ladder.

The never-finished, subterranean Battery Construction 129 lays below Hawk Hill. The shaft we climbed down topped out in what used to be an old lookout, before it was covered over at some point after WWII and a park built on top of it… and before one intrepid provocateur in the 80s, when the huge battery doors hadn’t been welded shut yet and the interior was still accessible to the general public, climbed the shaft, scrambled out the lookout opening, dug his way up through the dirt, and popped out of the ground, to the surprise of nearby parkgoers, then marking the spot with an overturned bucket with a rock on top of it before filling in the hole so nobody would spot it.

Note: Unfortunately, you can’t get in there at all any more. Some incredibly foolish egotist led a documentary film crew to the hole and brought them down into Battery 129, and the documentarians televised the video, which was seen by local officials who recognized the spot, and promptly filled the entry hole with a massive concrete plug, permanently sealing the last remaining access point to this hidden underground wonderland.

It’s still down there, though.

~ Click any image to enlarge ~

John, in his element. This is the entrance shaft we had to climb down, ladder at right.

The main gallery, at the bottom of the ladder. The interior of this complex used to be open to the public, hence the preponderance of 70s and 80s-era grafitti.

Graffiti, left over from when this place used to be wide open to the public in the 1980s.

In the main gallery. (the bald man is the late paul addis, who later gained a sort of national notoriety for prematurely torching burning man in 2007, leading to one of the greatest mugshots ever.)

In the large hallway that ran the length of the complex.

At one end of a long hallway, this sealed door led to the outside world.

The stairs down from the doorway.

One of two "altars" , large concrete blocks in the main gallery. The few explorers who get into this place traditionally leave notes and gifts here for posterity.

The second "altar". (if I recall correctly, "url" was the "urban research league", a group of people consisting of paul addis and a few other friends who consistently did such stupidly dangerous daredevil stuff that most people I knew avoided them.)

The curl of cigarette smoke is a reminder of the long-ago days when I had that habit. Graffiti indicates a groover has been here.

The bottom of the concrete entry shaft and ladder. It's easy to forget, looking at pictures, that we explored this all by flashlight, not by camera flash, and the whole experience looked much more like this photo than the others.

The area at the bottom of the entry shaft, off the main gallery.

The climb back to the surface, up a ladder up to a former lookout point. Since the complex was buried, the lookout point at the top of this shaft is now buried under several feet of dirt, and since about 20 years ago, concrete also, making us among the last people to see the inside of this place..