(covers information from several alternate timelines)
Alameda was a city located on an island in the San Francisco Metropolitan Area, California. The city was located across the San Francisco Bay from San Francisco. A road connected this city to Oakland and Bay Farm Island. In the late 20th century, the westernmost point of the city was home to the Alameda N.A.S., a US Navy base.
In 1986, the location of Alameda was depicted on a San Francisco Municipal Railway system map. In that year, the aircraft carrier, USS Enterprise (CVN-65) was docked at this base. Later that year, Pavel Chekov and Uhura were assigned by James T. Kirk to obtain uranium from a reactor of a nuclear vessel. The uranium would be used to recrystallize the dilithium on the HMS Bounty. The pair traced the uranium to this base, and eventually obtained the uranium from the number 4 main machine room of the Enterprise. (Star Trek IV: The Voyage Home)
In the alternate reality of 2259, the island on which Alameda was situated on was seen in a map of the San Francisco Bay. This map was part of a collection of graphics and video media that were displayed on a powerwall in the offices of Admirals Christopher Pike and Alexander Marcus at Starfleet Headquarters. (Star Trek Into Darkness)