Telfas Prime was the inhabited prime planet in its star system.
In the mid-24th century, a mining community was located here. It was here that Chakotay, while fighting off some miners, first met Kurt Bendera. Chakotay told this story at Bendera's funeral in 2372. (VOY: "Alliances")
This planet was only mentioned in dialogue.
According to StarTrek.com, Telfas Prime was located in or near the Demilitarized Zone along the Federation-Cardassian border. [1](X)