Stargate Atlantis is a science fiction tv program that "continues" Stargate SG-1 , the well know serial .
Atlantis is a city name of the ancients , the first race of humans that left Atlantis and the Pegasus galaxy and went to Earth .
If in the SG-1 the enemies of the people were the Goa'uld and The Ori , in SGA the enemies are a special race of aliens called The Wraith .
Our human expedition encounters lots of problems and hard times in fighting The Wraith and discovering the full potential of Atlantis City .