Market Street is a major thoroughfare in San Francisco, California. It begins at The Embarcadero in front of the Ferry Building at the northeastern edge of the city and runs southwest through downtown, passing the Civic Center and the Castro District, to the intersection with Portola Drive in the Twin Peaks neighborhood. Beyond this point, the roadway continues into the southwestern quadrant of San Francisco. Portola Drive extends south to the intersection of St. Francis Boulevard and Sloat Boulevard, where it continues as Junipero Serra Boulevard.
Market Street is the boundary of two street grids. Streets on its southeast side are parallel or perpendicular to Market Street, while those on the northwest are nine degrees off from the cardinal directions.
Market Street is a major transit artery for the city of San Francisco, and has carried in turn horse-drawn streetcars, cable cars, electric streetcars, electric trolleybuses, and diesel buses. Today Muni's buses, trolleybuses, and heritage streetcars share the street, while below the street the two-level Market Street subway carries Muni Metro and Bay Area Rapid Transit.