The new homeworld for the Tollan people following their evacuation from their dying home planet Tollan. The planet was originally settled by ships, as it had no Stargate. The Nox helped the Tollan to construct a new gate for their new home.
Tollana was protected by a network of advanced ion cannons, until the Goa'uld Anubis discovered shield and weapons technology that allowed his forces (commanded by the Goa'uld Tanith) to destroy the Tollan people.
Pretense - Narim summons SG-1 to the new homeworld, Tollana, for the triad of Klorel/Skaara.
Shades of Grey - SG-1 returns to Tollana to request advanced technology to defend against the Goa'uld, but O'Neill has darker options in mind.
Between Two Fires - SG-1 is summoned to Tollana for Omac's funeral, and is surprised to learn that the Tollan Curia is prepared to share their technology.