The Lunar Penal Colony was a human prison colony located on the Moon.
In an alternate timeline on 12 February 2144, Inspector Jill Sveinsdóttir warned the Fifth Doctor that he could be sent to the penal colony if he was convicted of a crime. (AUDIO: Repeat Offender)
In the 26th century, the prison was used for political dissidents; being sent there was a life sentence, and hardened criminals from regular prisons were hired as guards and warders. Professor Dale was one of several activists kept at the colony after they protested the war between the Earth and the Draconian Empires. The Third Doctor was also detained when he was believed to be a spy working for the Draconians. (TV: Frontier in Space) Máire Mab Finn set off bombs in an act of solidarity with the prisoners there. (PROSE: Love and War)
In 200,100, the Ninth Doctor, Jack Harkness and Lynda Moss were to be sent there the Lunar Penal Colony without trial after being caught disrupting games aboard the Game Station. (TV: Bad Wolf)