Atlan Island
From Transformers Wiki
Atlan Island (アトラン島 Atoran-tō) is located somewhere in southeast Asia, not far from the Karin Islands.
Fiction
Super-God Masterforce cartoon
Implementing a plan to sap the world's will to live by kidnapping all of the doctors, the Decepticon Pretenders utilized a cave on Atlan Island to house their prisoners. Doctor Dado, who had been attempting to treat a young girl named Copo, was taken there by Gilmer and discovered that Doctor Rhodan, who was needed to treat Copo, was also a captive of the Decepticons. Dado managed to escape, diving from a cliff and swimming out to sea. Drifting, he encountered the Autobot Godmasters and passed on the location of the captive medics. The Autobots launched a stealth attack on the island, successfully retrieving Doctor Rhodan, who was able to treat Copo.
Presumably, the Autobots returned to the island later and rescued the rest of the doctors. Save the Little Girl! The Chōjin Warriors, the Godmasters