San Francisco Cable cars are the only mobile National Monuments.
A third of commuters in San Francisco use public transportation in 2005. Public transit solely within the city of San Francisco is provided predominantly by the San Francisco Municipal Railway (Muni). The city-owned system operates both a combined light rail and subway system (the Muni Metro) and a bus network that includes trolleybuses, standard diesel motorcoaches and diesel hybrid buses. The Metro streetcars run on surface streets in outlying neighborhoods but underground in the downtown area.
Additionally, Muni runs the highly visible F Market historic streetcar line, which runs on surface streets from Castro Street to Fisherman’s Wharf (through Market Street), and the iconic San Francisco cable car system, which has been designated as a National Historic Landmark.