San Francisco cable cars are a historic mode of transportation in San Francisco, California. They were first introduced in 1873 and are the only manually operated cable car system still in use in the world. The cable cars run on tracks and are pulled by underground cables, allowing them to climb the city's steep hills. These iconic vehicles are a popular tourist attraction and provide a unique way to explore the city's famous neighborhoods. The cable car system is part of the San Francisco Municipal Transportation Agency and has been designated as a National Historic Landmark.