If you’ve ever found yourself wandering the steep, sun-drenched sidewalks of San Francisco's Potrero Hill, you might have stumbled upon a patch of land that feels… different. It isn’t a manicured park with irrigation lines and freshly painted benches. It’s a bit wilder. A bit windier. Honestly, it’s one of the few places in the city where you can actually see what the peninsula looked like before the concrete took over.
This is Starr King Open Space.
Most people call it a park. They’re technically wrong. It’s an "open space," a distinction that matters more than you’d think. While the city’s Recreation and Parks Department manages almost every other green square on the map, Starr King is a rebel. It’s owned by the people—specifically, a non-profit corporation run by the residents of Potrero Hill. It’s a 3.5-acre slice of history that almost didn't survive the 20th century.
The Geologic Secret Under Your Boots
You can’t talk about Starr King Open Space without talking about the ground itself. Ever notice how the rocks here have a weird, waxy, green sheen? That’s serpentinite, California’s official state rock.
Basically, this land is the eastern tip of a massive serpentine band that cuts diagonally across San Francisco, all the way from the Presidio. It’s not just pretty to look at; it’s actually a pretty hostile environment for most plants. Serpentine soil is heavy on magnesium and toxic metals like nickel, and it’s starving for calcium.
Most "invasive" European grasses—the ones that turn California hills gold in the summer—can’t handle it.
Because the soil is so tough, the native species have a fighting chance here. You’ve got the Golden Poppy, the Purple Needlegrass (our state grass, by the way), and a whole ecosystem of endemic plants that have evolved specifically to thrive in this "toxic" dirt. When you walk here in the spring, you aren't just looking at weeds. You're looking at a remnant of a prehistoric landscape.
Why Nobody Ever Built a House Here
It’s San Francisco. Every square inch of land is worth a fortune. So, how did 3.5 acres on a prime hilltop remain unbuilt?
Luck and a bit of a neighborhood fight.
Back in the 1960s and 70s, the land was part of a larger area targeted for development. Barratt Construction was working on the nearby Parkview Heights project. For a long time, the hilltop was basically a staging ground or just ignored. In 1984, the land was officially dedicated as open space.
But ownership is where it gets interesting.
The city didn’t want it. Or maybe the neighbors didn't want the city to have it. Regardless, it ended up in the hands of a 501(c)(3) non-profit. This means the Board of Directors—your neighbors—actually make the calls. They decide if the brush needs clearing or if a specific easement is going to be allowed. In 2010, there was a huge neighborhood dust-up when a developer tried to get a driveway easement through the space for a house on De Haro Street. The community went into full-defense mode, elected a new board, and made it very clear: this land is for the grass, the birds, and the people. Not cars.
The "Goat Lady" and the Community Spirit
If you’ve spent any time in Potrero, you might have heard of the "Goat Lady."
The adjacent Potrero Hill Community Garden sits on the slopes where she used to graze her herd. While the garden is technically separate (run by Rec and Parks), the vibe bleeds over into Starr King. There’s a sense of "slow action" here.
Recently, a group called Terremoto has been working on something they call a "Test Plot." Instead of coming in with a bulldozer and a bunch of nursery plants, they’re just... waiting. They spend hours weeding out specific invasives by hand—only the ones they can identify by name—to see what native seeds are still hiding in the soil. It's a practice in listening to the land rather than telling it what to do.
What to Actually Do There
Don't come here looking for a playground or a tennis court. You'll be disappointed.
Come here for the view. On a clear day, you’ve got a straight shot of the Golden Gate Bridge, the downtown skyline, and the Bay. It’s one of the best sunset spots in the city precisely because it isn't crowded.
- Hiking: The paths are mostly dirt and can get slippery when it’s wet. It’s a short loop, but the elevation change will wake up your calves.
- Disc Golf: There’s a tiny, informal 9-hole course known as "Putt Hill." It’s basically just for putters and casual play. Don't expect a pro-level layout; expect to hit a bush or two.
- Wildflower Walks: If you're lucky enough to visit when Ralph Hunter (the local geologist and botany expert) is leading a walk, go. He knows every rock and sprout on that hill.
A Few Real-Talk Rules
Because this is a sensitive ecosystem, things are a little different than at Dolores Park.
First off, keep the drones at home. They freak out the birds and ruin the "urban refuge" vibe the board works so hard to maintain. Second, while people do bring dogs, you’ve got to be careful. The board and local volunteers are constantly trying to protect the native grasses from being trampled or over-fertilized by, well, dog waste. High nitrogen levels from pets actually help the invasive grasses take over the native ones.
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Also, watch out for coyotes. They live here. They were here first, and they’re pretty comfortable roaming the tall grass at dusk.
Actionable Insights for Your Visit
If you’re planning to head up to Carolina and 23rd Street, keep these things in mind to make the most of it:
Timing is everything. Go in late March or April. That’s when the serpentine soil really shows off. The poppies and needlegrass are at their peak, and the "green" rocks look incredible against the spring growth.
Check the wind. Potrero Hill is famously sunny, but Starr King is an exposed ridge. If the fog is rolling in through the Golden Gate, it’s going to whip across that hilltop. Bring a windbreaker even if it feels warm down on 18th Street.
Volunteer. The space exists because of labor. They have regular stewardship days (usually mentioned on their website or local newsletters). If you want to understand the difference between French Broom and a native shrub, show up for a weeding session.
Respect the boundaries. Stay on the established paths. It’s tempting to scramble up the rocks for a photo, but that’s exactly how the rare Manzanitas and other sensitive plants get crushed into the dirt.
Starr King Open Space isn't a park you just consume. It's a piece of San Francisco's soul that requires a little more respect and a little less "amenity" than the rest of the city. Walk slow, look at the rocks, and maybe leave a small donation to the non-profit that keeps the developers at bay.