Tellar, also called Tellar Prime, was a Class M planet that was home to the humanoid Tellarites.
Relative to the planetoid Babel, it was located on the far side of the Andorian Empire. (ENT: "Babel One")
Good arguments were considered a sport on Tellar. (ENT: "Bounty")
In 2155, it became one of the founding members of the Coalition of Planets and later, in 2161, the United Federation of Planets. (ENT: "Demons", "Zero Hour")
Following the fall of Betazed during the Dominion War, in 2374, it was believed that Tellar could be the Dominion's next target. (DS9: "In the Pale Moonlight")
The world boasted a famed space elevator, which rose from the surface into low orbit.
The Starfleet School of Engineering was located on the planet.