P9X-391
From The Stargate Omnipedia
Planet believed to once be the home of an Ancient colony. SG-1, who described the world as sandy and windy, located an interdimensional visibility device within the antechamber of the Ancient ruins.
DETAILS
HOME TO - Uninhabited
FIRST APPEARED - Sight Unseen
KEY EPISODE
Sight Unseen - SG-1 returns from P9X-391 with an unusual device believed to be of Ancient origin.