Stargate Atlantis follows the adventures of a human expedition to the lost city of Atlantis in the Pegasus Galaxy. The Stargate has brought humanity into contact with other cultures, including new and powerful enemies: the Wraith, the Genii, and later the Asurans, all while trying to uncover the secrets the Ancients left behind.Stargate Atlantis premiered on the US Sci Fi Channel on July 16 2004 with “Rising”, a movie-style two-part episode.