P3X-474 was a planet in the Milky Way galaxy which held a Stargate and DHD. The Odyssey, while under attack from the Ori, traveled to the planet and beamed down all of its crew except General Landry and SG-1, so that they could return to Earth safely. Shortly after, SG-1 created a time dialation field to protect themselves from an incoming blast form an Ori mothership. They were inside of it for around 50 years before they finally figured out a way to reverse the field and escape. (SG1: "Unending")