San Francisco 4th and King Street station, also known as the Caltrain Depot, is a train station in the SoMa district of San Francisco, California. It is presently the northern terminus of the Caltrain commuter rail line serving the San Francisco Peninsula and Santa Clara Valley. It is also the eastern terminus of the N Judah and E Embarcadero, as well as a stop along the T Third Street of the Muni network. The station is additionally the projected terminus for the first phase of the California High-Speed Rail project and a station once Phase 2 is completed.

The E Embarcadero is a historic streetcar line that is the San Francisco Municipal Railway's second heritage streetcar line in San Francisco, California. Trial service first ran during the Sunday Streets events on The Embarcadero in 2008. The line initially ran on weekends only, but expanded to weeklong service in late April 2016.