The Tenderloin’s beloved bathhouse is back — and hotter than ever

Onsen Bathhouse, a Japanese communal bathing space in the Tenderloin, reopened for business Friday after a five-year hiatus. Sandwiched between an auto-body shop and The Healing Well, a dilapidated building where free yoga classes are offered to unhoused people, is a beautiful, 3,200-square-foot retreat with a steam room, redwood sauna, cold plunge, and 15-person heated soaking pool.

“This is a place to get some tranquility in an otherwise chaotic universe,” said Adam Wren, Onsen’s former general manager and new owner, who notes that unlike many traditional bathhouses, Onsen doesn’t enforce silence. “We don’t shy away from the social aspect of the bathhouse — we allow conversation.”

The reopening comes amid a turbulent period for San Francisco’s clothing-optional communal sauna scene. Russian bath Archimedes Banya in Bayview faced heat for a now-rescinded guest policy for transgender people; Japantown’s Imperial Day Spa also received criticism from trans guests. Both spas have since updated their policies. 

Onsen, Wren said, is a fully inclusive space, on coed days and during gender-specific time slots. “Our policy is, if you identify as a gender, you’re welcome to come in,” he said. “We’re accepting of everyone.”

Still, the recent episodes served as a stark reminder that San Francisco, for all its free-love legacy, has few communal bathhouses. Contributing to the bathhouse drought is bureaucratic red tape. Until recent years, AIDS-era laws had banned private rooms and placed permit approval under the jurisdiction of the San Francisco Police Department. In 2020, Supervisor Rafael Mandelman began dismantling that legislation and, in 2024, successfully repealed SFPD oversight. “We’ve come a long way on the way to bring back gay bathhouses to San Francisco,” Mandelman said in a statement last year.

Two new venues catering to a gay clientele — Castro Baths and New Bathhouse — are in the works, though neither has announced an opening date.

Onsen opened in 2016 inside a converted auto-body shop, repurposing the mechanics pit into an eight-person heated pool. It also housed a well-regarded, 20-seat restaurant that served sashimi, hibachi skewers, kimchi, and tea. Both closed in 2020 due to citywide Covid shutdowns. 

“We’re really excited to see places like Onsen reopen,” said Anne Cannady, cofounder of Alchemy Springs, a sauna and bathhouse in Lower Nob Hill, and founder of the North American Bathing Operator Community. “Social sauna and bathing is certainly taking off in San Francisco.”

Onsen 2.0 brings a few upgrades, Wren said. The wilted plants have been replaced, the pools have been serviced, and the store stocks local artisanal goods from Ember + Fog and Heliotrope. The bathhouse also updated its reservation system to Tock in preparation for the return of food service in June.

Wren, who has worked as wine director and manager for restaurants that include Mr. Jiu’s, Automat, and Commonwealth, said he has secured a chef with a Michelin star to run the 25-seat dining room and 10-seat private room. “It will be Japanese-influenced with California ingredients,” he said, and will offer yakitori, sashimi, and bento boxes — and a seven-course, post-spa tasting menu.

Wren hopes Onsen’s serene atmosphere will soothe the mind and spirit of its patrons and the neighborhood as well. The reopening, he believes, may shift the “Fox News perception” of the Tenderloin. “We want this to be a space where people can connect,” he said. “This is a third space.”