Rura Penthe

Located in the Mempa Sector in the Beta Quadrant, the frozen planetoid was in the U.S.S. Discovery's search area for Captain Lorca when he was taken by the Klingons. 

A high-security prison was located underground, as the surface weather was inhospitable and unable to support life. The conditions on Rura Penthe meant that being inarcerated there was as good as a death sentence, and many prisoners were forced to work under terrible conditions in the dilithium mines.

Captain Archer served a short time at Rura Penthe before being rescued by his crew.

Kirk and McCoy also served time on Rura Penthe after being falsly accused of assasinating Chancellor Gorkon in 2293.