The Sen'lanarc Mountains was a region on the planet Romulus, situated on the continent of Novok. It was the source of the Balsanra River, the H'relgath River and the Tai'eld River.
The southern Sen'lanarc Mountains were once extensively mined for minerals, including gold, silver, rubies, emeralds, veraktite and traxanite. (Last Unicorn RPG - The Way of D'era: The Romulan Star Empire module: The Romulans)