Rarotonga is the most populous island in a group of islands known as the Cook Islands in the Pacific Ocean on Earth, and houses the capital city.
Christine Vale's uncle and aunt owned land on Rarotonga, and Vale took leave and vacationed on the island between the USS Enterprise-E's inspection tour in late 2379 and their experiences at Romulus with Praetor Shinzon. William T. Riker came to visit her after the Enterprise returned to Earth for repair, and again offered her the position of first officer aboard the USS Titan (TNG novel: A Time for War, A Time for Peace)