P2X-639 is a planet in the Milky Way galaxy which has a Stargate. In 2004, SG-6 explored the planet and found the ruins of a Sumerian temple in a mountain. SG-1 explored the temple but got stuck in the temple mountain system in a tunnel collapse with the team being exposed to a variant of anthrax. A rescue team eventually saved SG-1 from the tunnel. (SG1: "Pathogen")