For a long time, it was thought that the Goa'uld were the builders of the Stargate Network, but it was later discovered that they had merely made use of the relics left behind by a different and extinct race, the Ancients. At the climax of "SG-1"'s 6th season, Daniel Jackson discovers that the Earth myth of Atlantis is in fact founded on the Lost City of the Ancients, and Season 7 is spent trying to locate it. At the beginning of the show "Stargate Atlantis", which coincides with the beginning of "SG-1"'s 8th season, the city is found in the Pegasus Galaxy, and 8 chevrons are dialed to send an expedition there on what could be a one-way trip. It is there that they discover a new network of stargates, and are plagued by the nemesis of the Ancients, the Wraith. During the events of "The Ark of Truth", it is revealed that the pre-ascended Ancient known as Amelius originated the concept of the Stargate and wormhole travel.