Beta Site

The Beta site is the Tau'ri's secondary off-world base. Two separate worlds have been referred to as the Beta Site. However, it has never appeared onscreen.

Alternate Beta Site
When Daniel Jackson used the Quantum Mirror to travel to an alternate reality where Apophis invaded Earth the Alpha site was refferd to as the Beta site.

Current Beta Site
The current Beta site was used to evacuate Alpha site personnel to when it was attacked by Anubis.