Homeworld of the Athosians, a small agrarian population oppressed by the Wraith for countless generations. Athos was routinely under siege by Wraith culling parties until John Sheppard evacuated Teyla's village to Atlantis for safe harbor following a Wraith attack. The planet Athos was, as far as we know, left uninhabited.
Not far from the Athosians' village is an ancient city which appears to possess more advanced technology than that which the Athosians retained in their nomadic village. Colonel Marshall Sumner and his team from Earth was unable to explore it before the Wraith attacked. Several kilometers from the village lies a hidden chamber where Teyla believes her descendants once hid from the Wraith. It is covered in writings and images depicting previous attacks.
It is not known if any other Athosian villages remained behind on the planet following the most recent Wraith attack, after which the Athosians in Teyla's village relocated to Atlantis. They later settled on another planet, naming it "New Athos."
Rising, Part 1 - Sumner and his team travel to Athos in the hopes of locating additional Zero Point Modules to power Atlantis, but the planet is attacked by Wraith.
Rising, Part 2 - Following the Wraith attack, the Athosian survivors leave their homeworld for Atlantis.
Missing - Teyla goes to visit her people on New Athos, but finds they have all gone missing.