Hayes Valley, San Francisco

Based on Wikipedia: Hayes Valley, San Francisco

In January 2023, a venture capitalist named Amber Yang coined a term that would stick: Cerebral Valley. She was describing something peculiar happening in a San Francisco neighborhood called Hayes Valley. Young artificial intelligence researchers were packing into Victorian houses, hosting hackathons in living rooms, and building the next generation of AI systems within walking distance of each other. The name was a play on Silicon Valley, but with a twist—this wasn't about silicon chips anymore. It was about brains, or at least about machines that could think like them.

But to understand how a neighborhood of ornate Victorian townhouses became the unlikely epicenter of the AI revolution, you have to go back further. Much further.

From Wildflowers to World-Changing Technology

Before San Francisco existed, before Spain claimed California, the land that would become Hayes Valley was covered in wildflowers every spring. The Ohlone people, living in small bands across the region, gathered food from the seasonal creeks that cut through the area. One of these waterways, Hayes Creek, ran diagonally through what is now the neighborhood's commercial district. Today that creek flows underground year-round, invisible beneath boutiques and coffee shops, a geological ghost.

The Spanish arrived in 1776 with the Juan Bautista de Anza expedition, establishing Mission San Francisco de Asís just south of what would become Hayes Valley. Then came the California Gold Rush of 1849, which transformed San Francisco from a small settlement into a boomtown almost overnight. Italian immigrants from the Genoa region recognized opportunity in the sandy soil and established produce farms in the area.

The neighborhood's name comes from a man named Thomas Hayes, who served as San Francisco's county clerk from 1853 to 1856. His brother Michael sat on the committee that named the streets when the Western Addition was developed in the 1850s to expand the city westward from Van Ness Avenue. Whether Michael's advocacy for naming a street after his brother was pure nepotism or genuine recognition of Thomas's contributions remains a matter lost to history.

A Tale of Two Architectures

The Victorians who built up Hayes Valley in the late nineteenth century had a particular genius for class stratification embedded in urban planning. The primary streets—Hayes, Gough, McAllister—were named for influential citizens and lined with grand Victorian and Queen Anne mansions. The smaller side streets, where the craftspeople who built those mansions lived, received botanical names: Lily, Ivy, Linden, Hickory. The social hierarchy was literally mapped onto the landscape.

This accident of urban planning would later prove significant. When the devastating earthquake struck San Francisco on April 18, 1906, the fires that followed destroyed much of the city. But Hayes Valley, south of McAllister Street, was spared. Those Victorian houses survived, and they still stand today—now some of the most expensive real estate in the city, and home to the AI hacker houses that gave Cerebral Valley its name.

The neighborhood's demographic story is one of successive waves. After World War II, Hayes Valley and the broader Western Addition became a predominantly African-American neighborhood, part of the flourishing Black community centered on the nearby Fillmore district. Jazz clubs thrived. Businesses prospered.

Then came urban renewal—a term that, in American cities, often meant the opposite of what it sounds like. By the mid-1980s, Hayes Valley was considered one of the most dangerous neighborhoods in the Bay Area. The elevated Central Freeway, part of U.S. Route 101, had been built through the neighborhood in the 1950s, severing communities and depressing property values along its shadow.

The Freeway That Changed Everything

October 17, 1989. The Loma Prieta earthquake struck during the World Series, which happened to be an all-Bay Area matchup between the Oakland Athletics and San Francisco Giants. The earthquake killed 63 people, collapsed sections of the Bay Bridge, and damaged the Central Freeway running through Hayes Valley.

What happened next became one of the most consequential debates in San Francisco's modern history.

The city closed the damaged freeway, and activists led by Patricia Walkup campaigned for its complete demolition rather than repair. This was controversial. Freeways move cars, and cars move commuters, and commuters vote. But Walkup and her allies won. The elevated freeway came down.

In its place, the city built Octavia Boulevard—a tree-lined street that ends at a small park between Fell and Hayes streets. That park is now called Patricia's Green, named for Walkup after her death, a monument to what determined local activism can achieve. The park features rotating public art installations, a playground, and something that elevated freeways never provide: community gathering space.

The freeway's demolition triggered rapid gentrification. Within years, Hayes Valley transformed from one of the city's most troubled neighborhoods into one of its trendiest. Boutiques replaced boarded-up storefronts. High-end restaurants opened. The Victorian houses that had survived earthquake and urban decay became highly desirable—not despite their age, but because of it.

A Brief Agricultural Interlude

For a few years, the lots where the freeway's on-ramps had stood became something unexpected: a farm.

Hayes Valley Farm opened in 2010 on 2.2 acres of city-owned land between Fell and Oak streets. It was an experiment in urban permaculture, a demonstration that food could be grown even in the heart of a dense city. Community volunteers tended crops under an interim use agreement—everyone understood the land would eventually be developed.

In 2012, that development was approved. The farm gave way to an Avalon apartment complex, one of many such transitions in American cities where land is too valuable to grow vegetables. But for three years, there had been a working farm in the middle of San Francisco, which is either a wonderful anomaly or a sad commentary on urban land economics, depending on your perspective.

The Arts Take Root

Hayes Valley's proximity to San Francisco's Civic Center—home to City Hall, the main library, and the performing arts complex—has shaped its cultural character. San Francisco Opera was founded in 1923. San Francisco Ballet followed in 1933. Both are among the oldest and most respected companies of their kind in the United States.

In 2013, something new joined them: the SFJAZZ Center, described as the first freestanding building in the western United States built specifically for jazz performance and education. The building's opening represented a kind of homecoming. Jazz had been central to the neighborhood's identity in the mid-twentieth century, when the nearby Fillmore district was known as the "Harlem of the West." The SFJAZZ Center was, in a sense, a monument to that history.

Enter the Hackers

The pandemic changed many things, but one of its stranger effects was on where young tech workers wanted to live.

During COVID-19, Big Tech companies allowed remote work, and many employees scattered. Some moved to cheaper cities. Others went home to be near family. San Francisco's tech scene, which had defined the city's economy for a decade, seemed to be dissipating.

Then, in late 2022, something shifted. ChatGPT launched, and suddenly artificial intelligence wasn't an abstract research topic—it was a product millions of people were using. The AI boom had begun.

The timing coincided with massive layoffs across Big Tech. Companies like Meta, Google, and Amazon shed tens of thousands of workers. Many of these newly unemployed engineers were young, talented, and suddenly free to pursue their own projects. Some gathered in group houses.

The "hacker house" concept wasn't new. In Silicon Valley's mythology, great companies emerge from garages and group houses—Apple from the Jobs family garage, Facebook from a Harvard dorm room and then various houses in Palo Alto. But the AI hacker houses that sprouted in Hayes Valley starting in 2021 and 2022 had a particular character.

Many were based in the neighborhood's Victorian homes near Alamo Square. The irony was rich: houses built in the nineteenth century to display the wealth of railroad barons and mining magnates were now hosting twenty-somethings building large language models and neural networks. The original craftspeople who built these houses couldn't have imagined electricity, let alone artificial intelligence.

What Makes a Valley Cerebral

By the time Amber Yang of Bloomberg Beta coined "Cerebral Valley" in early 2023, the phenomenon was already well underway. Hacker houses like AGI House and Genesis House had become nodes in an informal network. The event-listing app Partiful showed a growing number of gatherings advertising their location as "Cerebral Valley" rather than "Hayes Valley" or "San Francisco."

Garry Tan, president of Y Combinator—the legendary startup accelerator that had funded companies like Airbnb, Dropbox, and Stripe—declared in April 2023 that Hayes Valley had become Cerebral Valley. Coming from one of the most influential figures in Silicon Valley, this was something close to an official coronation.

The Cerebral Valley AI Summit, hosted by tech journalist Eric Newcomer and the voice-AI startup Volley, formalized what had been happening organically. Suddenly, a neighborhood that many San Franciscans had watched transform from dangerous to trendy was transforming again—into something that felt, to observers, like a return to Silicon Valley's roots.

There's something deliberately nostalgic about the Cerebral Valley phenomenon. The San Francisco Standard noted that the hacker houses and their associated "grind culture" echoed the early days of companies like Facebook, when Mark Zuckerberg and his cofounders lived and worked in the same space, blurring the line between life and labor. Whether this is inspiring or concerning depends on how you feel about that kind of intensity.

The Geography of Innovation

Why Hayes Valley? Why not the Mission, or SoMa, or any of the other neighborhoods where tech workers had traditionally clustered?

Part of the answer is practical. Hayes Valley's Victorian housing stock provides large homes with multiple bedrooms—perfect for group living arrangements. The neighborhood sits at a transportation nexus, with multiple MUNI bus lines and the Van Ness Avenue subway station providing access throughout the city. The commercial strip along Hayes Street offers the coffee shops, restaurants, and casual meeting spaces that creative workers seem to require.

But part of the answer might be aesthetic. There's something about working on cutting-edge technology in a nineteenth-century house that appeals to a certain sensibility. It suggests continuity rather than rupture—that the future being built is connected to the past, not a rejection of it.

The neighborhood's boundaries remain, as they always have been, somewhat vague. The Hayes Valley Neighborhood Association defines them one way. The San Francisco Association of Realtors defines them another, more expansively. The overlap with the Lower Haight to the south creates confusion. But in a sense, this ambiguity is appropriate for Cerebral Valley, which is less a geographic designation than a state of mind.

Ghosts and Futures

Hayes Creek still flows under Hayes Valley, invisible. The Ohlone people who gathered food along its banks are remembered, if at all, only in the collective name assigned to them by later arrivals. Thomas Hayes, the county clerk who lent his name to the street, left little other legacy. The African-American community that thrived here in the mid-twentieth century has largely dispersed, priced out by the same gentrification that made the neighborhood attractive to tech workers.

Every city is a palimpsest, each era's writing partially visible beneath the next. Hayes Valley might be the clearest example in San Francisco—a place where Indigenous history, Spanish colonization, Gold Rush development, Victorian grandeur, postwar Black culture, urban decay, freeway construction, earthquake damage, activist demolition, boutique gentrification, and now AI hacker houses have layered on top of each other.

The young engineers in the Victorian hacker houses are building systems that might, if their ambitions are realized, change human civilization in ways we can barely imagine. They're doing this in houses built by craftspeople whose tools were hand planes and chisels, in a neighborhood that was farmland not so long ago, on land where the Ohlone once gathered seasonal foods.

Whether Cerebral Valley represents a genuine renaissance in American innovation or merely another chapter in San Francisco's endless cycle of boom and displacement remains to be seen. What's certain is that the neighborhood will continue to transform. It always has. Hayes Creek will keep flowing underground, indifferent to whatever happens on the surface, connecting this moment to every moment before it.