Atlantis Base
From The Stargate Omnipedia
Radio call sign used as the designation for the Atlantis team's home base in the Pegasus Galaxy -- the city of Atlantis.
Shortly after the beginning of the Atlantis expedition, the city's radio call sign was shortened to a less formal "Atlantis."
See also: Atlantis command tower
KEY EPISODE
Rising, Part 1 - The Atlantis team gates to the command deck of Atlantis to discover it to be intact and pristine.