The Alameda Mole was a transit and transportation facility in Alameda, California for ferries landing in the East Bay of San Francisco from 1878 to the 1930s. It was located on the west end of Alameda, and later became part of the Alameda Naval Air Station. It was one of four neighboring moles. The others were the Oakland Mole, the WP Mole, and the Key System Mole. The purpose of the mole was to extend tracks of rail-based transportation lines beyond the shallow mud flats along the shore of the East Bay into water deep enough to accommodate the passenger and rail ferries to San Francisco.