The planet had a large amount of celebium - a radioactive material which with prolonged exposure was fatal to humanoid life, and as a result recent visitors have had to rely of shielding to protect them from the celebium.
Janice Lester was sent to Camus II with an archaeological team to investigate the planet in the late 2260s. She found a machine there that let her change bodies, which she later did with James T. Kirk. (TOS episode: "Turnabout Intruder")
In 2371, when the crew of Deep Space 9 were preparing for a Dominion attack, Jadzia Dax arranged for a warp-capable transport ship to be permanently stationed in the Bajoran arctic. If the Jem'Hadar should attack the station, its civilian population and non-essential Starfleet personnel would be taken to the transport, which would then take them to Camus II. Federation personnel would be waiting for them there. (DS9 novelization: The Search)