Juna designated P3X-729 and P2X-729 by the Tau'ri, was a planet originally under the domain of the Goa'uldHeru'ur, home to a pre-industrialized human population.
SG-1 arrived and informed the people they no longer had to worship Heru'ur (possibly following his death) and instructed them to bury the Stargate.
Unfortunately, after Apophis destroyed Heru'ur, Cronus stepped in and laid claim to Juna, unearthed the Stargate and forced the locals to worship him or face annihilation.
This forced the robotic Jack O'Neill to contact the real SG-1 for help in stopping Cronus. The real SG-1 eventually arrived on the planet and with the assistance of their robot selves was able to defeat Cronus but tragically, all of the robotic SG-1 were killed during the fight.
Juna is deciduous in plant life, but much of it is dead or dying. The landscape is of dark browns and many grays, barely appearing to be an adequate environment for the human population, who smear themselves in the planet's ample supplies of mud and other filth in disguise from invaders. Juna's Naquadah-mines are empty. (SG1: "Double Jeopardy")