The twin planet of Romulus, a tidally locked world where the Reman people were forced to labor as miners and soldiers.
Remus is the sister planet of Romulus in the Romulan system. One side faces its sun permanently, while the other lies in darkness, and the Remans live in its dark hemisphere, forced by the Romulans to work in dilithium mines and serve as front-line troops.
In Star Trek: Nemesis, Shinzon, a clone of Picard abandoned on Remus as a child, rises to lead the Remans. He builds the warship Scimitar and seizes power in the Romulan Empire.