From The Stargate Omnipedia
Great Ring of Avidan
Term the Tegalans
called the Stargate
, before their learned of its more common name. The Great Ring was discovered in the Corillian wastelands
, and became a centerpiece of the planet's societies.
The Great Ring eventually became so significant that it was responsible for plunging the countries into a devastating war which almost wiped out all of Tegalus's inhabitants.
Icon - SG-1's arrival through the Great Ring of Avidan forces all of a planet to reassess its belief system (and dealings with their neighbors), for the worse.