Argentia

Argentia was a densely-populated planet and tax haven visited by the Fifth Doctor (AUDIO: Serpent in the Silver Mask) and the Seventh Doctor. (AUDIO: Kingdom of Silver)

The Fifth Doctor arrived with Adric, Tegan and Nyssa, looking to acquire a diothanine crystal so he could make a new sonic screwdriver. Here they were admitted into the funeral of wealthy mining magnate Carlo Mazzini. When his son Angelo was murdered the planet was put on temporal lock-down, with no time travelling vehicles being able to come and go. (AUDIO: Serpent in the Silver Mask)