10 Deadliest Alien Prisons In Doctor Who
4. The Dalek Asylum
Surrounded by a dense forcefield and a killer nanocloud, this snowcapped world held captive some of the most deranged Daleks in the universe.
Mountainous and remote, the Dalek Asylum, from the outside, looked more like an unassuming ski resort than an institute for insane Daleks. The interior, however, hosted a network of dingy, abandoned tunnels and crumbling medical facilities. Inside this labyrinth were intensive care units and prison cells bursting with the worst of the worst of the Dalek race.
The Daleks incarcerated in the Asylum were either ancient and decrepit or survivors of conflicts with the Doctor. Variants from throughout Doctor Who history were present in the prison, including Emperor's Guards from 1967 and the Special Weapons Dalek from 1988.
Fully automated, with the security nanocloud programmed to slowly convert intruders into zombified Dalek Puppets, this was both a deadly prison and a lethal planet.
Even the Daleks were terrified of the Asylum - sending the Eleventh Doctor through the forcefield on a mission to destroy it in 2012's Asylum of the Daleks. With the help of Oswin, a former starship crewmember-turned-Dalek, the planet's forcefield was lowered and the Doctor and his friends managed to repair a teleport before the Asylum was decimated by a missile strike.
Intergalactic Travel Advice: Escape route not included.