The log in Merlin's phase-shift device revealed the gate address to PX1-767, the planet on which Merlin had hidden his weapon capable of destroying ascended beings. SG-1 visited the planet in search of the device and found the village of Camelot, the past and future home of King Arthur and his Knights of the Round Table. Despite a thorough search of Merlin's library, the weapon was not to be found, however SG-1 learned from Meurik, the governor of Camelot, that the Sangreal they sought might be found on Castiana, Sahal, or Vagon Brei. Eventually a combination of the coordinates for those three worlds produced a gate address that would lead to Merlin's weapon.
Episode Reference: Camelot
Stargate Coordinates: 20-2-35-8-26-15