Tài Sum was a small city located on Installation 05 following it's Colonization at the climax of the First Human-Covenant War. It was the first city of the ring to begin construction and the first one complete. Unlike the other cities of the ring, it did not become a massive megapolis like city (mostly due to the Battle it became involved in that ended in it's destruction). Unlike Sagawitchewan and Scotsguard it only had a population made of Humans and Sangheli.