Thousands of Muni riders pass through Eureka Valley Station every day, but no trains ever stop.

Located about 100 yards west of Castro Street Station, beneath the asphalt of Market Street, Eureka Valley is Muni’s ghost station, a term used around the world to describe subway stations that have been abandoned but still have trains full of passengers pass through them regularly.

San Francisco’s lone ghost station may or may not be haunted — only the spirits know — but it is a bit eerie. When trains roll through the dark and dusty station every few minutes, it becomes noisy and windy. Then it falls into silence, interrupted intermittently by the sounds of cars rumbling across a ventilation grate on the street overhead.

Four Muni Metro lines pass through the station on their way between Forest Hill Station, deep inside the Twin Peaks Tunnel, and Castro Street Station. But most passengers don’t look up from their cell phones, and it’s not clear that anyone is even aware of the abandoned station’s existence.

During a recent class instructing fifth-graders on how to navigate Muni on their own, the students pressed against the window, looking for the ghost station their instructor had promised would appear in the murky underground.

“I see it, I see it,” some shouted as the L-Taraval train rolled through.

Frankly, there’s not much to see — a low boarding platform and a single wooden bench on each side, separated from the tracks by cyclone fences. There are a couple of doors and stairways that lead to the street, and rows of concrete pillars supporting the station’s ceiling.

Eureka Valley Station sits just inside the east portal to the Twin Peaks Tunnel, where Municipal Railway streetcars descended from Market Street into darkness or vice versa.

The station was built in 1914, when work on the tunnel began, and served millions of streetcar riders traveling up and down Market Street and into or out of the Twin Peaks tunnel. It was closed in 1972, and the entrances to the station from Market Street were demolished as Muni prepared to put trains underground in the Market Street Subway.

Eureka Valley Station’s demise was not mourned, according to a 1972 article in The Chronicle. Hardly anyone was sorry to see it go, wrote Chronicle staff writer Carl Nolte. The station, whose stairways had a dogleg in them, were frequented by muggers and rapists. It was, he wrote “a place as dangerous as any in the city.”

Michael Macor/The Chronicle

The station was also a good spot for police to catch up to motorists who drove through the tunnel accidentally or intentionally. And it was popular with juveniles playing the risky game of “nipping the fender,” which entailed hitching a ride on the rear bumper of a streetcar.

Although Eureka Valley Station is no longer in service, it remains a critical part of the Muni Metro system, said John Haley, transit manager for the Municipal Transportation Agency.

The old tracks and ramps descending from Market Street into the tunnel are surrounded by grass and weeds, but Muni crews use them regularly to perform overnight maintenance and repairs at the Twin Peaks tunnel and Market Street Subway.

“This allows us to more efficiently maintain the system,” Haley said. “We use it, if not every night, four nights a week.”

Muni also keeps up maintenance to the entrances and exits to the station for use in case of emergencies. The sidewalk entrances, near Eureka Street, are covered with steel plates that can be unlocked and lifted.

For years after the station closed, it was frequented by miscreants using it for parties, as a place to sleep, or for subterranean romantic rendezvous.

“I’ve heard lots of stories about goings-on in this station,” Haley said, “but none of them are fit for a family newspaper.”

Over the years, Muni has secured the empty station, installing new doors and gates as well as security cameras.

“We keep it tightly locked up,” Haley said.

Historically, the notion of ghost stations started with the division of Berlin, and its subway system, at the beginning of the Cold War. Subway lines were severed or restricted and several stations closed.

About 30 ghost stations exist in the U.S., nine on the New York City subway system. But Eureka Valley seems to be the only one in the Bay Area.

Some consider Doolittle Station, the wheelhouse and control center for BART’s Oakland Airport Connector, to be a ghost station, because it was once planned as a stop. But that would-be station is above ground and was never really abandoned.

Michael Cabanatuan is a San Francisco Chronicle staff writer. Email: mcabanatuan@sfchronicle.com Twitter: @ctuan