Rura Penthe is a dilithium-rich asteroid used as a penal colony by the Klingon Empire. As the extremely low surface temperature of Rura Penthe makes it uninhabitable by most life forms, the mines are located underground. This "Gulag" is known the galaxy over as "The Alien's Graveyard". (TOS movie: The Undiscovered Country)
- Star Trek: Nero states Rura Penthe's location to be the Laurentian system, but all other sources place it in the Beta Penthe system.
Life in the penal colony is extremely harsh, with few prisoners surviving more than a year. Therefore, a sentence to the mines of Rura Penthe is one of the most feared punishments throughout the galaxy, often said to be worse than death. The penal colony has no stockade, guard tower or electronic frontier. It only has a magnetic shield that extends over a significant part of the planet's surface, preventing transporter use. As well as its warden's animals resembling both a Klingon targ and Terran sabre-tooth tiger. The most common form of punishment given to prisoners is banishment to the freezing surface, where they don't survive for long. One of the prison's commandants in the late 23rd century made a point of banishing at least one troublemaker each time that new prisoners arrived, so that they would know from the start the penalty for working badly or disobeying the rules. (TOS movie: Star Trek VI: The Undiscovered Country)
At some point after he delivered his information to the Klingon High Council in 2151, Klaang was sentenced to life at Rura Penthe to his being dishonored by being saved by humans. (ST reference: Federation: The First 150 Years)
The only known escapees from Rura Penthe are Earth Starfleet Captain Jonathan Archer in 2152, and Starfleet Captain James T. Kirk and Commander Leonard McCoy in 2293. (ENT episode: "Judgment"; TOS movie: Star Trek VI: The Undiscovered Country)
In 2371, the Warden of Rura Penthe was involved in a plot to assassinate Chancellor Gowron. In turn, the warden was assassinated by agents of the Klingon Honor Guard. (TNG video game: Klingon Honor Guard)
In the year 2409, a recently promoted Klingon crew journeyed to Rura Penthe in search of Franklin Drake. Here, the crew and their captain also discovered a prisoner named K'mtar, who claims that the House of Martok is in danger from the House of Torg. Drake convinces the crew to listen to him, escaping as he does. (STO mission: "Manhunt")
In 2233 of an alternate reality, the Narada sat crippled near Klingon space and soon attracted the attention of the Klingons. A fleet led by Captain Kor of the IKS Klothos attacked. The Narada's crew did their best to repel the Klingons, but despite killing many could not hold back the stronger Klingon force. The Narada's crew was detained on Rura Penthe, while the Narada was put in orbit above. There Nero was brutally interrogated by the prison's commandant, Koth and his guards.
Twenty-five years later in 2258 the Narada's crew escaped Rura Penthe and reclaimed the Narada, destroying forty-seven Klingon warbirds in the process. Following the Destruction of Vulcan, two Romulans, Arix and Vella, were left behind there and were brutally question about the future they came from. They then killed the guard and escaped to continue their mission.(TOS - Nero comics: "Number One", "Number Two", "Number Four"; TOS - Legacy of Spock comic: "Part 1", TOS novelization: Star Trek)