A Klingon prison planet where Kirk and McCoy were held in Star Trek VI.
Rura Penthe is a frozen Klingon penal colony, known to many as the Aliens' Graveyard. It is a bleak and icy world where prisoners are forced to work in the mines, and its harsh conditions make escape nearly impossible. It is feared throughout the quadrant as a place from which few return.
The prison is guarded by few soldiers, because the cold and the lack of any place to go are themselves enough to keep inmates in place. Prisoners are not free to leave, and they have little hope of survival if they do. The colony is known to be a place for those who have angered the Klingon authorities.
Rura Penthe is best known from Star Trek VI: The Undiscovered Country, in which Kirk and McCoy are sentenced to life there after being convicted of the murder of Chancellor Gorkon. They meet a shapeshifter named Martia, who helps them to escape, and Spock then mounts a rescue. The colony is also mentioned in other series, and remains a symbol of Klingon justice at its harshest.