Zeta Minor
From Tardis Wiki, the free Doctor Who reference
Zeta Minor was the planet farthest out in the known universe. It contained a link to a universe of anti-matter. The planet had a jungle-like terrain and was home to Anti-matter creatures.
In the year 37166, the Fourth Doctor and Sarah Jane Smith responded to a distress call from a scientific expedition on Zeta Minor. A space crew landed shortly after their arrival on the planet. (TV: Planet of Evil)
