Eskal, designated P4Z-326 by the Tau'ri, was a planet in the Milky Way galaxy which was used as a base of operations by Hathor. She built a pyramid, the internal sections of which were a mock-up of the SGC, to decieve SG-1 (minus Teal'c) into believing that they had been frozen in stasis and over eighty years had passed. The Tok'ra managed to send information to Earth, and a rescue mission lead by Colonel Robert Makepeace succeeded in rescuing SG-1, with some help from Teal'c and General Hammond.
Behind the scenes
Stargate SG-1: The DVD Collection issue 15 identifies one of the chevrons for this planet as the point of origin for Earth. However, this could not be possible due to the fact that the point of origin only appears on that gate.